View source for Quetiapine

{{Short description|Atypical antipsychotic medication}}
{{Pp-semi-indef}}
{{Use dmy dates|date=January 2024}}
{{cs1 config|name-list-style=vanc|display-authors=6}}
{{Infobox drug
| Watchedfields = changed
| verifiedrevid = 443404910
| image = Quetiapine.svg
| image_class = skin-invert-image
| width = 250
| alt = 
| caption = 
| image2 = Quetiapine-from-xtal-3D-balls.png
| width2 = 225

<!--Clinical data-->
| pronounce = {{IPAc-en|k|w|ᵻ|ˈ|t|aɪ|.|ə|p|iː|n}} {{respell|kwi|TY|ə-peen}}
| tradename = Seroquel, Seroquel Xr, others
| Drugs.com = {{drugs.com|monograph|quetiapine-fumarate}}
| MedlinePlus = a698019
| DailyMedID = Quetiapine
| pregnancy_AU = B3
| pregnancy_category = 
| routes_of_administration = [[Oral administration|By mouth]]
| ATC_prefix = N05
| ATC_suffix = AH04
| class = [[Atypical antipsychotic]]

| legal_AU = S4
| legal_AU_comment = <ref>{{cite web | title=Prescription medicines: registration of new generic medicines and biosimilar medicines, 2017 | website=Therapeutic Goods Administration (TGA) | date=21 June 2022 | url=https://www.tga.gov.au/resources/publication/publications/prescription-medicines-registration-new-generic-medicines-and-biosimilar-medicines-2017 | access-date=30 March 2024}}</ref>
| legal_BR = C1
| legal_BR_comment = <ref>{{cite web |author=Anvisa |author-link=Brazilian Health Regulatory Agency |date=31 March 2023 |title=RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial |trans-title=Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control|url=https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |url-status=live |archive-url=https://web.archive.org/web/20230803143925/https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |archive-date=3 August 2023 |access-date=16 August 2023 |publisher=[[Diário Oficial da União]] |language=pt-BR |publication-date=4 April 2023}}</ref>
| legal_CA = Rx-only
| legal_UK = POM
| legal_US = Rx-only
| legal_US_comment = <ref name="dailymed PI" /><ref>{{cite web | title=Seroquel Xr- quetiapine tablet, extended release | website=DailyMed | date=27 January 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=473a3ac4-67f4-4782-baa9-7f9bdd8761f4 | access-date=22 September 2024}}</ref>
| legal_status = 

<!--Pharmacokinetic data-->
| bioavailability = 100%<ref name = Medscape />
| metabolism = [[Liver]] via CYP3A4-catalysed sulfoxidation to its active metabolite norquetiapine (N-desalkylquetiapine)<ref name = GG>{{cite book| vauthors = Brunton L, Chabner B, Knollman B |title=Goodman and Gilman's The Pharmacological Basis of Therapeutics|edition=12th|publisher=McGraw Hill Professional|year=2010|isbn=978-0-07-162442-8|url=https://books.google.com/books?id=bVUfAQAAQBAJ}}</ref>
| protein_bound = 83%<ref name=EMC>{{cite web|title=Quetiapine 25 mg film-coated tablets - Summary of Product Characteristics|date=January 2013|access-date=20 October 2013|website=electronic Medicines Compendium|publisher=Sandoz|url=http://www.medicines.org.uk/emc/medicine/26575/SPC/Quetiapine+25+mg+film-coated+tablets/|archive-url=https://web.archive.org/web/20131020062812/http://www.medicines.org.uk/emc/medicine/26575/SPC/Quetiapine+25+mg+film-coated+tablets/|archive-date=20 October 2013}}</ref>
| elimination_half-life = 7 hours (parent compound); 9–12 hours (active metabolite, norquetiapine)<ref name = EMC/><ref name = DD>Truven Health Analytics, Inc. DrugPoint System (Internet) [cited 2013 Sep 18]. Greenwood Village, CO: Thomsen Healthcare; 2013.</ref>
| excretion = [[Kidney]] (73%), feces (20%)<ref name=Medscape>{{cite web|title=quetiapine (Rx) - Seroquel, Seroquel XR|url=http://reference.medscape.com/drug/seroquel-xr-quetiapine-342984#10|website=Medscape Reference|publisher=WebMD|access-date=11 October 2013|url-status = live|archive-url=https://web.archive.org/web/20131020163700/http://reference.medscape.com/drug/seroquel-xr-quetiapine-342984#10|archive-date=20 October 2013}}</ref><ref name = EMC/><ref name = DD /><ref name=DM>{{cite web|title=Quetiapine fumarate tablet |website=DailyMed|publisher=Ascend Laboratories, LLC|date=October 2013|access-date=26 November 2013|url=https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=3112a006-1c61-47f2-84f5-9a7670d09c9b|url-status = live|archive-url=https://web.archive.org/web/20131202224630/http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=3112a006-1c61-47f2-84f5-9a7670d09c9b|archive-date=2 December 2013}}</ref>

<!--Identifiers-->
| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 111974-69-7
| PubChem = 5002
| IUPHAR_ligand = 50
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB01224
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 4827
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = BGL0JSY5SI
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D08456
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 8707
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 716

<!--Chemical data-->
| IUPAC_name = 2-(2-(4-Dibenzo[''b'',''f''][1,4]thiazepine-11-yl-1-piperazinyl)ethoxy)ethanol
| C = 21| H = 25| N = 3| O = 2| S = 1
| SMILES = N\1=C(\c3c(Sc2c/1cccc2)cccc3)N4CCN(CCOCCO)CC4
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C21H25N3O2S/c25-14-16-26-15-13-23-9-11-24(12-10-23)21-17-5-1-3-7-19(17)27-20-8-4-2-6-18(20)22-21/h1-8,25H,9-16H2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = URKOMYMAXPYINW-UHFFFAOYSA-N
| solubility = 3.29
}}

<!-- Definition and medical uses -->
'''Quetiapine''' ({{IPAc-en|k|w|ᵻ|ˈ|t|aɪ|.|ə|p|iː|n}} {{respell|kwi|TY|ə-peen}}), sold under the brand name '''Seroquel''' among others, is an [[atypical antipsychotic]] medication used in the treatment of [[schizophrenia]], [[bipolar disorder]], bipolar depression, and [[major depressive disorder]].<ref name=AHFS2017>{{cite web|title=Quetiapine Fumarate|url=https://www.drugs.com/monograph/quetiapine-fumarate.html|publisher=The American Society of Health-System Pharmacists|access-date=26 March 2017|url-status = live|archive-url=https://web.archive.org/web/20170829153057/https://www.drugs.com/monograph/quetiapine-fumarate.html|archive-date=29 August 2017}}</ref><ref name=Cochrane2010>{{cite journal | vauthors = Komossa K, Depping AM, Gaudchau A, Kissling W, Leucht S | title = Second-generation antipsychotics for major depressive disorder and dysthymia | journal = The Cochrane Database of Systematic Reviews | issue = 12 | article-number = CD008121 | date = December 2010 | volume = 2012 | pmid = 21154393 | doi = 10.1002/14651858.CD008121.pub2 | pmc = 11994262 }}</ref> Despite being widely prescribed as a [[sleep aid]] due to its [[Tranquilizer|tranquillizing]] effects, the benefits of such use may not outweigh the risk of undesirable side effects.<ref>{{cite journal | vauthors = Anderson SL, Vande Griend JP | title = Quetiapine for insomnia: A review of the literature | journal = American Journal of Health-System Pharmacy | volume = 71 | issue = 5 | pages = 394–402 | date = March 2014 | pmid = 24534594 | doi = 10.2146/ajhp130221 | url = https://pdfs.semanticscholar.org/8812/afd4bc713c03435b68f2bb6ea456c611b0b2.pdf | s2cid = 207292819 | archive-url = https://web.archive.org/web/20200219013637/https://pdfs.semanticscholar.org/8812/afd4bc713c03435b68f2bb6ea456c611b0b2.pdf | archive-date = 19 February 2020 }}</ref> It is taken orally.<ref name=AHFS2017/>

<!-- Side effects and mechanism -->
Common side effects include [[Somnolence|sedation]], [[fatigue]], weight gain, [[constipation]], and [[dry mouth]].<ref name=AHFS2017/> Other side effects include [[orthostatic hypotension|low blood pressure with standing]], [[seizures]], [[high blood sugar]], [[tardive dyskinesia]], and [[neuroleptic malignant syndrome]].<ref name=AHFS2017/> In older people with [[dementia]], its use increases the risk of death.<ref name=AHFS2017/> Use in the [[third trimester]] of [[pregnancy]] may result in a [[movement disorder]] in the baby for some time after birth.<ref name=AHFS2017/> Quetiapine is believed to work by blocking a number of receptors, including those for [[serotonin receptor|serotonin]] and [[dopamine receptors|dopamine]].<ref name=AHFS2017/>

<!-- History and culture -->
Quetiapine was developed in 1985 and was approved for medical use in the United States in 1997.<ref name="dailymed PI" /><ref name=AHFS2017/><ref>{{cite journal | vauthors = Riedel M, Müller N, Strassnig M, Spellmann I, Severus E, Möller HJ | title = Quetiapine in the treatment of schizophrenia and related disorders | journal = Neuropsychiatric Disease and Treatment | volume = 3 | issue = 2 | pages = 219–235 | date = April 2007 | pmid = 19300555 | pmc = 2654633 | doi = 10.2147/nedt.2007.3.2.219 | doi-access = free }}</ref> It is available as a [[generic medication]].<ref name=BNF74>{{cite book|title=British national formulary: BNF 74|date=2017|publisher=British Medical Association|isbn=978-0-85711-298-9|page=383|edition=74}}</ref> In 2023, it was the most prescribed antipsychotic and 60th most commonly prescribed medication in the United States, with more than 10{{nbsp}}million prescriptions.<ref>{{Cite web |title=The Top 300 of 2023 |url=https://clincalc.com/DrugStats/Top300Drugs.aspx |archive-url=https://web.archive.org/web/20250812130026/https://clincalc.com/DrugStats/Top300Drugs.aspx |archive-date=2025-08-12 |access-date=2025-08-13 |website=clincalc.com}}</ref><ref>{{Cite web |title=Quetiapine - Drug Usage Statistics, ClinCalc DrugStats Database |url=https://clincalc.com/DrugStats/Drugs/Quetiapine |access-date=2025-08-13 |website=clincalc.com}}</ref> It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO23rd">{{cite book | vauthors = ((World Health Organization)) | title = The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023) | year = 2023 | hdl = 10665/371090 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2023.02 | hdl-access=free }}</ref>  

The drug is typically among two antipsychotics (the other being [[olanzapine]]) to have superior efficacy for the treatment of bipolar disorder. Quetiapine is one of only two antipsychotics (the other is [[cariprazine]]) that produce equal efficacy as standalone therapies for mixed manic-depressive mood swings as they do in combination with an [[Selective serotonin reuptake inhibitor|SSRI]] antidepressant. But it is less potent than [[clozapine]], [[amisulpride]], [[olanzapine]], [[risperidone]], and [[paliperidone]] in alleviating [[Psychosis|psychotic]] symptoms or treating schizophrenia.

==Medical uses==
[[File:Seroquel-25mg.jpg|thumb|Quetiapine (Seroquel) 25 mg tablets, next to [[Penny (United States coin)|US one-cent]] coin for comparison]]
[[File:SeroquelXR150.jpg|thumb|Seroquel XR 150 mg tablet box]]

Quetiapine is primarily used to treat schizophrenia and bipolar disorder.<ref name=AHFS>{{cite web|title=quetiapine-fumarate|url=https://www.drugs.com/monograph/quetiapine-fumarate.html|website=The American Society of Health-System Pharmacists|access-date=3 April 2011|url-status = live|archive-url=https://web.archive.org/web/20110210181855/http://www.drugs.com/monograph/quetiapine-fumarate.html|archive-date=10 February 2011}}</ref> It targets both positive and negative symptoms of schizophrenia.<ref name="Quetiapine">{{cite journal | vauthors = Dev V, Raniwalla J | title = Quetiapine: a review of its safety in the management of schizophrenia | journal = Drug Safety | volume = 23 | issue = 4 | pages = 295–307 | date = October 2000 | pmid = 11051217 | doi = 10.2165/00002018-200023040-00003 }}</ref>

===Schizophrenia===
A 2013 Cochrane [[Systematic review|review]] compared quetiapine to typical antipsychotics: 
{| class="wikitable"
|+ Quetiapine compared to typical antipsychotics for schizophrenia<ref name=Sut2013>{{cite journal | vauthors = Suttajit S, Srisurapanont M, Xia J, Suttajit S, Maneeton B, Maneeton N | title = Quetiapine versus typical antipsychotic medications for schizophrenia | journal = The Cochrane Database of Systematic Reviews | volume = 2013 | issue = 5 | article-number = CD007815 | date = May 2013 | pmid = 23728667 | doi = 10.1002/14651858.CD007815.pub2 | url = http://www.cochrane.org/CD007815/SCHIZ_quetiapine-versus-typical-antipsychotic-drugs-for-schizophrenia | url-status = live | archive-url = https://web.archive.org/web/20160421052117/http://www.cochrane.org/CD007815/SCHIZ_quetiapine-versus-typical-antipsychotic-drugs-for-schizophrenia | archive-date = 21 April 2016 | pmc = 11931684 }}</ref>
|-
! Summary
|-
|Quetiapine may not differ from typical [[antipsychotic]]s in the treatment of [[Schizophrenia#Positive_symptoms|positive symptoms]], general psychopathology, and [[Schizophrenia#Negative_symptoms|negative symptoms]]. However, it causes fewer adverse effects in terms of abnormal [[Electrocardiography|ECG]], [[Extrapyramidal symptoms|extrapyramidal]] effects, abnormal prolactin levels and weight gain.<ref name=Sut2013/>
|-
| style="padding:0;" |
{| class="wikitable collapsible collapsed" style="width:100%;"
|-
! scope="col" style="text-align: left;"| Outcome
! scope="col" style="text-align: left;"| Findings in words
! scope="col" style="text-align: left;"| Findings in numbers
! scope="col" style="text-align: left;"| Quality of evidence
|-
! colspan="4" style="text-align: left;"| Global state
|-
| No clinical significant response || There is no clear difference between people given quetiapine and those receiving typical antipsychotic drugs. These findings are based on data of moderate quality. || [[Relative risk|RR]] 0.96 (0.75 to 1.23) || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
! colspan="4" style="text-align: left;"|Mental state
|-
| Average [[Schizophrenia#Positive_symptoms|positive symptom]] score ([[Positive and Negative Syndrome Scale|PANSS]])|| On average, people receiving quetiapine scored higher (worse) than people treated with typical antipsychotic drugs. There was, however, no clear difference between the groups. This finding is based on data of moderate quality. || [[Mean absolute difference|MD]] 0.02 higher (0.39 lower to 0.43 higher)* || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
| Average [[Schizophrenia#Negative_symptoms|negative symptom]] score ([[Positive and Negative Syndrome Scale|PANSS]])|| On average, people receiving quetiapine scored lower (better) than people treated with typical antipsychotic drugs. This finding is based on data of moderate quality. || [[Mean absolute difference|MD]] 0.82 lower (1.59 to 0.04 lower)* || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
! colspan="4" style="text-align: left;"| [[Cognition|Cognitive function]]
|-
| Average score|| On average, people receiving quetiapine scored higher (better) than people treated with typical antipsychotic drugs. There was no clear difference between the groups. This finding is based on data of very limited quality. || [[Mean absolute difference|MD]] 1.55 higher (0.62 lower to 3.72 higher)* || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Very low]]
|-
! colspan="4" style="text-align: left;"| Leaving the study early
|-
| For any reason || Quetiapine is not clearly more acceptable than typical antipsychotic drugs. These findings are based on data of moderate quality. || [[Relative risk|RR]] 0.91 (0.81 to 1.01) || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
! colspan="4" style="text-align: left;"| Adverse effects
|-
| Extrapyramidal effects || Quetiapine may reduce the chance of experiencing these movement disorders. This finding is based on data of moderate quality. || [[Relative risk|RR]] 0.17 (0.09 to 0.32) || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
| Prolactin level<br />Average level (ng/mL) || On average, people receiving quetiapine scored lower (better) than people treated with typical antipsychotic drugs. There was a clear difference between the groups. This finding is based on data of moderate quality.|| [[Mean absolute difference|MD]] 16.20 lower (23.34 to 9.07 lower)* || [[The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach|Moderate]]
|-
| || *The meaning of these findings for day-to-day care is not clear || ||
|}
|}

In a 2013 comparison of 15 antipsychotics in effectiveness in treating schizophrenia, quetiapine demonstrated standard effectiveness. It was 13–16% more effective than [[ziprasidone]], [[chlorpromazine]], and [[asenapine]] and approximately as effective as [[haloperidol]] and [[aripiprazole]].<ref name=Lancet/>

There is tentative evidence of the benefit of quetiapine versus placebo in schizophrenia; however, definitive conclusions are not possible due to the high rate of attrition in trials (greater than 50%) and the lack of data on economic outcomes, social functioning, or quality of life.<ref name=Coch2004>{{cite journal | vauthors = Srisurapanont M, Maneeton B, Maneeton N | title = Quetiapine for schizophrenia | journal = The Cochrane Database of Systematic Reviews | issue = 2 | article-number = CD000967 | year = 2004 | volume = 2004 | pmid = 15106155 | pmc = 7032613 | doi = 10.1002/14651858.CD000967.pub2 | veditors = Srisurapanont M }}</ref>

It is debatable whether, as a class, [[typical antipsychotics|typical]] or [[atypical antipsychotic]]s are more effective.<ref>{{cite journal | vauthors = Kane JM, Correll CU | title = Pharmacologic treatment of schizophrenia | journal = Dialogues in Clinical Neuroscience | volume = 12 | issue = 3 | pages = 345–357 | year = 2010 | pmid = 20954430 | pmc = 3085113 | doi = 10.31887/DCNS.2010.12.3/jkane }}</ref> Both have equal drop-out and symptom relapse rates when typicals are used at low to moderate dosages.<ref name=AFP07>{{cite journal | vauthors = Schultz SH, North SW, Shields CG | title = Schizophrenia: a review | journal = American Family Physician | volume = 75 | issue = 12 | pages = 1821–1829 | date = June 2007 | pmid = 17619525 }}</ref> While quetiapine has lower rates of extrapyramidal side effects, there is greater sleepiness and rates of dry mouth.<ref name=Coch2004/>

A Cochrane review comparing quetiapine to other atypical antipsychotic agents tentatively concluded that it may be less efficacious than [[olanzapine]] and [[risperidone]]; produce fewer movement related side effects than [[paliperidone]], [[aripiprazole]], [[ziprasidone]], risperidone and olanzapine; and produce weight gain similar to risperidone, [[clozapine]] and aripiprazole. It found that quetiapine produces suicide attempts; death; QTc prolongation, [[low blood pressure]]; [[tachycardia]]; sedation; [[gynaecomastia]]; [[galactorrhoea]], [[menstrual irregularity]], and decline in [[white blood cell count]] at a rate similar to first-generation antipsychotics.<ref name="Asmal L, Flegar SJ, Wang J, Rummel-Kluge C, Komossa K, Leucht S 2013 CD006625">{{cite journal | vauthors = Asmal L, Flegar SJ, Wang J, Rummel-Kluge C, Komossa K, Leucht S | title = Quetiapine versus other atypical antipsychotics for schizophrenia | journal = The Cochrane Database of Systematic Reviews | volume = 2013 | issue = 11 | article-number = CD006625 | date = November 2013 | pmid = 24249315 | pmc = 4167871 | doi = 10.1002/14651858.CD006625.pub3 }}</ref>

===Bipolar disorder===
In those with [[bipolar disorder]], quetiapine is used to treat depressive episodes; acute manic episodes associated with [[bipolar I disorder]] (as either monotherapy or adjunct therapy to [[Lithium pharmacology|lithium]]; [[Valproic acid|valproate]] or [[lamotrigine]]); acute mixed episodes; and maintenance treatment of bipolar I disorder (as adjunct therapy to lithium or divalproex).

===Major depressive disorder===
Quetiapine is effective when used by itself<ref name =Cochrane2010/> and when used along with other medications in [[major depressive disorder]] (MDD),<ref name =Cochrane2010/><ref>{{cite journal | vauthors = Spielmans GI, Berman MI, Linardatos E, Rosenlicht NZ, Perry A, Tsai AC | title = Adjunctive atypical antipsychotic treatment for major depressive disorder: a meta-analysis of depression, quality of life, and safety outcomes | journal = PLOS Medicine | volume = 10 | issue = 3 | article-number = e1001403 | year = 2013 | pmid = 23554581 | pmc = 3595214 | doi = 10.1371/journal.pmed.1001403 | doi-access = free }}</ref> but sedation is often an undesirable side effect.<ref name =Cochrane2010/>

In the United States,<ref name = "DD" /> the United Kingdom<ref name = "BNF 65" /> and Australia (while not subsidised by the Australian [[Pharmaceutical Benefits Scheme]] for treatment of MDD), quetiapine is licensed for use as an add-on treatment in MDD.<ref name = "AMH">{{cite book | title = Australian Medicines Handbook | year = 2013 | publisher = The Australian Medicines Handbook Unit Trust | isbn = 978-0-9805790-9-3 | edition = 2013 | place = Adelaide | veditors = Rossi S | url = https://books.google.com/books?id=tn3-swEACAAJ }}</ref>

===Alzheimer's disease===
Quetiapine does not decrease agitation among people with [[Alzheimer's disease]]. Quetiapine worsens intellectual functioning in the elderly with dementia and therefore is not recommended.<ref name="Ballard Margallo-Lana Juszczak Douglas et al : Quetiapine and rivastigmine and cognitive decline in Alzheimer's disease: randomised double blind placebo controlled trial">{{cite journal | vauthors = Ballard C, Margallo-Lana M, Juszczak E, Douglas S, Swann A, Thomas A, O'Brien J, Everratt A, Sadler S, Maddison C, Lee L, Bannister C, Elvish R, Jacoby R | title = Quetiapine and rivastigmine and cognitive decline in Alzheimer's disease: randomised double blind placebo controlled trial | journal = BMJ | volume = 330 | issue = 7496 | page = 874 | date = April 2005 | pmid = 15722369 | pmc = 556156 | doi = 10.1136/bmj.38369.459988.8F }}</ref>

===Insomnia===
The use of low doses of quetiapine for [[insomnia]], while common, is not recommended; there is little evidence of benefit and concerns regarding adverse effects.<ref name="pmid22510671">{{cite journal | vauthors = Coe HV, Hong IS | title = Safety of low doses of quetiapine when used for insomnia | journal = The Annals of Pharmacotherapy | volume = 46 | issue = 5 | pages = 718–722 | date = May 2012 | pmid = 22510671 | doi = 10.1345/aph.1Q697 | s2cid = 9888209 }}</ref><ref name="pmid24534594">{{cite journal | vauthors = Anderson SL, Vande Griend JP | title = Quetiapine for insomnia: A review of the literature | journal = American Journal of Health-System Pharmacy | volume = 71 | issue = 5 | pages = 394–402 | date = March 2014 | pmid = 24534594 | doi = 10.2146/ajhp130221 }}</ref><ref name="pmid33941603">{{cite journal | vauthors = Modesto-Lowe V, Harabasz AK, Walker SA | title = Quetiapine for primary insomnia: Consider the risks | journal = Cleveland Clinic Journal of Medicine | volume = 88 | issue = 5 | pages = 286–294 | date = May 2021 | pmid = 33941603 | doi = 10.3949/ccjm.88a.20031 | doi-access = free }}</ref><ref name="pmid22132426">{{cite report | vauthors = Maglione M, Maher AR, Hu J, Wang Z, Shanman R, Shekelle PG, Roth B, Hilton L, Suttorp MJ, Ewing BA, Motala A, Perry T | title = Off-Label Use of Atypical Antipsychotics: An Update | date = September 2011 | pmid = 22132426 }}</ref><ref name="Off-Label Use">{{cite book |title=Off-Label Use of Atypical Antipsychotics: An Update |vauthors=Maglione M, Maher AR, Hu J, Wang Z, Shanman R, Shekelle PG, Roth B, Hilton L, Suttorp MJ |publisher=Agency for Healthcare Research and Quality |year=2011 |series=Comparative Effectiveness Reviews, No. 43 |location=Rockville |pmid=22973576}}</ref><ref>{{cite journal | vauthors = Coe HV, Hong IS | title = Safety of low doses of quetiapine when used for insomnia | journal = The Annals of Pharmacotherapy | volume = 46 | issue = 5 | pages = 718–722 | date = May 2012 | pmid = 22510671 | doi = 10.1345/aph.1Q697 | s2cid = 9888209 }}</ref> A 2022 network meta-analysis of 154 double-blind, randomized controlled trials of drug therapies vs. placebo for insomnia in adults found that quetiapine did not demonstrate any short-term benefits in sleep quality. Quetiapine, specifically, had an [[effect size]] ([[standardized mean difference]]) against [[placebo]] for treatment of insomnia of 0.05 (95% {{Abbrlink|CI|confidence interval}} –1.21 to 1.11) at 4{{nbsp}}weeks of treatment, with the [[certainty of evidence]] rated as very low.<ref>{{cite journal | vauthors = De Crescenzo F, D'Alò GL, Ostinelli EG, Ciabattini M, Di Franco V, Watanabe N, Kurtulmus A, Tomlinson A, Mitrova Z, Foti F, Del Giovane C, Quested DJ, Cowen PJ, Barbui C, Amato L, Efthimiou O, Cipriani A | title = Comparative effects of pharmacological interventions for the acute and long-term management of insomnia disorder in adults: a systematic review and network meta-analysis | language = English | journal = Lancet | volume = 400 | issue = 10347 | pages = 170–184 | date = July 2022 | pmid = 35843245 | doi = 10.1016/S0140-6736(22)00878-9 | s2cid = 250536370 | doi-access = free | hdl = 11380/1288245 | hdl-access = free }}</ref> Doses of quetiapine used for insomnia have ranged from 12.5 to 800{{nbsp}}mg, with low doses of 25 to 200{{nbsp}}mg being the most typical.<ref name="pmid19299326">{{cite journal | vauthors = Wine JN, Sanda C, Caballero J | title = Effects of quetiapine on sleep in nonpsychiatric and psychiatric conditions | journal = The Annals of Pharmacotherapy | volume = 43 | issue = 4 | pages = 707–713 | date = April 2009 | pmid = 19299326 | doi = 10.1345/aph.1L320 | s2cid = 207263320 }}</ref><ref name="pmid22510671" /><ref name="pmid24534594" /> Regardless of the dose used, some of the more serious adverse effects may still possibly occur at the lower dosing ranges, such as [[dyslipidemia]] and [[neutropenia]].<ref>{{cite journal | vauthors = Pillinger T, McCutcheon RA, Vano L, Mizuno Y, Arumuham A, Hindley G, Beck K, Natesan S, Efthimiou O, Cipriani A, Howes OD | title = Comparative effects of 18 antipsychotics on metabolic function in patients with schizophrenia, predictors of metabolic dysregulation, and association with psychopathology: a systematic review and network meta-analysis | journal = The Lancet. Psychiatry | volume = 7 | issue = 1 | pages = 64–77 | date = January 2020 | pmid = 31860457 | pmc = 7029416 | doi = 10.1016/s2215-0366(19)30416-x }}</ref><ref>{{cite journal | vauthors = Yoshida K, Takeuchi H | title = Dose-dependent effects of antipsychotics on efficacy and adverse effects in schizophrenia | journal = Behavioural Brain Research | volume = 402 | article-number = 113098 | date = March 2021 | pmid = 33417992 | doi = 10.1016/j.bbr.2020.113098 | s2cid = 230507941 | doi-access = free }}</ref> Increases in serum triglycerides, LDL-C, and fasting blood glucose have been observed following quetiapine treatment at doses typically used off-label in the treatment of insomnia.<ref>{{cite journal | vauthors = Carr CN, Lopchuk S, Beckman ME, Baugh TB | title = Evaluation of the use of low-dose quetiapine and the risk of metabolic consequences: A retrospective review | journal = The Mental Health Clinician | volume = 6 | issue = 6 | pages = 308–313 | date = November 2016 | pmid = 29955487 | pmc = 6007538 | doi = 10.9740/mhc.2016.11.308 }}</ref><ref>{{cite journal | vauthors = Højlund M, Støvring H, Andersen K, Correll CU, Hallas J | title = Impact of low-dose quetiapine-use on glycosylated hemoglobin, triglyceride and cholesterol levels | journal = Acta Psychiatrica Scandinavica | volume = 147 | issue = 1 | pages = 105–116 | date = January 2023 | pmid = 36281759 | pmc = 10099591 | doi = 10.1111/acps.13515 }}</ref> These safety concerns at low doses are corroborated by Danish observational studies that showed use of specifically low-dose quetiapine (prescriptions filled for tablet strengths >50 mg were excluded) was associated with an increased risk of major cardiovascular events as compared to use of [[Z-drugs]], with most of the risk being driven by cardiovascular death.<ref>{{cite journal | vauthors = Højlund M, Andersen K, Ernst MT, Correll CU, Hallas J | title = Use of low-dose quetiapine increases the risk of major adverse cardiovascular events: results from a nationwide active comparator-controlled cohort study | journal = World Psychiatry | volume = 21 | issue = 3 | pages = 444–451 | date = October 2022 | pmid = 36073694 | pmc = 9453914 | doi = 10.1002/wps.21010 }}</ref> Laboratory data from an unpublished analysis of the same cohort also support the lack of dose-dependency of metabolic side effects, as new use of low-dose quetiapine was associated with a risk of increased fasting triglycerides at 1-year follow-up.<ref>{{cite thesis | vauthors = Højlund M | degree = Ph.D. | publisher = University of Southern Denmark |date=12 September 2022 |title=Low-dose Quetiapine: Utilization and Cardiometabolic Risk |url= https://portal.findresearcher.sdu.dk/en/publications/low-dose-quetiapine-utilization-and-cardiometabolic-risk |language=English |doi=10.21996/mr3m-1783}}</ref>

===Others===

It is sometimes used [[off-label]], often as an augmentation agent, to treat conditions such as [[Tourette syndrome]],<ref name="Mukaddes_2013">{{cite journal | vauthors = Mukaddes NM, Abali O | title = Quetiapine treatment of children and adolescents with Tourette's disorder | journal = Journal of Child and Adolescent Psychopharmacology | volume = 13 | issue = 3 | pages = 295–299 | year = 2003 | pmid = 14642017 | doi = 10.1089/104454603322572624 }}</ref> [[musical hallucinations]]<ref>Oliver Sacks "Musicophilia" Knopf NY 2007 P.67</ref> and [[anxiety disorder]]s.<ref name="Becker : Treatment of sleep dysfunction and psychiatric disorders">{{cite journal | vauthors = Becker PM | title = Treatment of sleep dysfunction and psychiatric disorders | journal = Current Treatment Options in Neurology | volume = 8 | issue = 5 | pages = 367–375 | date = September 2006 | pmid = 16901376 | doi = 10.1007/s11940-006-0026-6 | s2cid = 34246401 }}</ref>

Quetiapine and [[clozapine]] are the most widely used medications for the treatment of [[Parkinson's disease]] psychosis due to their relatively low extrapyramidal side-effect liability.<ref>{{cite journal | vauthors = Kyle K, Bronstein JM | title = Treatment of psychosis in Parkinson's disease and dementia with Lewy Bodies: A review | journal = Parkinsonism & Related Disorders | volume = 75 | pages = 55–62 | date = June 2020 | pmid = 32480308 | doi = 10.1016/j.parkreldis.2020.05.026 | quote = In clinical practice, quetiapine is more readily used than clozapine, given its improved side effect profile compared to clozapine. Despite frequent use in clinical practice, its efficacy in PDP is less clear.&nbsp;... The quetiapine evidence base is thus ambiguous, lacking consistent support from RCTs in PDP. In DLB there is reliance upon retrospective studies, with the inherent limitations therein. As with clozapine, sedation and orthostasis can be limiting factors. In clinical practice, despite the paucity of consistent evidence, quetiapine has been the first line antipsychotic therapy due to its side effect profile and lower neuroleptic sensitivity risk. | s2cid = 219168745 }}</ref> Owing to the risks associated with clozapine (e.g. agranulocytosis, diabetes mellitus, etc.), clinicians often attempt treatment with quetiapine first, although the evidence to support quetiapine's use for this indication is significantly weaker than that of clozapine.<ref>{{cite journal | vauthors = Shotbolt P, Samuel M, David A | title = Quetiapine in the treatment of psychosis in Parkinson's disease | journal = Therapeutic Advances in Neurological Disorders | volume = 3 | issue = 6 | pages = 339–350 | date = November 2010 | pmid = 21179595 | pmc = 3002640 | doi = 10.1177/1756285610389656 }}</ref><ref name = Maudsley/>

==Adverse effects==
Sources for incidence lists:<ref name = Medscape /><ref name = "DD"/><ref name = "BNF 65">{{cite book|title=British National Formulary (BNF) 65|year=2013|publisher=Pharmaceutical Press|location=London, UK|isbn=978-0-85711-084-8|page=235|url=https://books.google.com/books?id=fZLvtHELVdMC}}</ref><ref name = AMH /><ref name = Maudsley>{{cite book| vauthors = Taylor D, Carol P, Shitij K |title=The Maudsley prescribing guidelines in psychiatry|year=2012|publisher=Wiley-Blackwell|location=West Sussex|isbn=978-0-470-97969-3|url=https://books.google.com/books?id=KY_2Qk4LqVYC}}</ref><ref name=TGA>{{cite web |title= PRODUCT INFORMATION STADA(TM) Quetiapine (quetiapine fumarate Tablets 25 mg, 100 mg, 200 mg, 300 mg)|url=https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2012-PI-03014-1|date=30 November 2012|access-date=19 September 2013|website=TGA eBusiness Services|publisher=STADA Pharmaceuticals Australia Pty Limited|url-status = live|archive-url=https://web.archive.org/web/20170327075724/https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2012-PI-03014-1|archive-date=27 March 2017}}</ref>

;Very common (>10% incidence) adverse effects
* Dry mouth
* Dizziness
* Headache
* [[Somnolence]] (drowsiness; of 15 antipsychotics quetiapine causes the 5th most sedation. Extended release (XR) formulations tend to produce less sedation, dose-by-dose, than the immediate release formulations.)<ref name=Lancet>{{cite journal | vauthors = Leucht S, Cipriani A, Spineli L, Mavridis D, Orey D, Richter F, Samara M, Barbui C, Engel RR, Geddes JR, Kissling W, Stapf MP, Lässig B, Salanti G, Davis JM | title = Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis | journal = Lancet | volume = 382 | issue = 9896 | pages = 951–962 | date = September 2013 | pmid = 23810019 | doi = 10.1016/S0140-6736(13)60733-3 | s2cid = 32085212 }}</ref>

;Common (1–10% incidence) adverse effects
{{colbegin|colwidth=15em}}
* [[Hypertension|High blood pressure]]
* [[Orthostatic hypotension]]
* [[Tachycardia|High pulse rate]]
* [[Hypercholesterolaemia|High blood cholesterol]]
* Elevated serum triglycerides
* Abdominal pain
* Constipation
* Increased appetite
* Vomiting
* Increased liver enzymes
* Backache
* [[Asthenia]]
* Insomnia
* Lethargy
* Tremor
* Agitation
* Nasal congestion
* [[Pharyngitis]]
* Fatigue
* Pain
* [[Dyspepsia]] (Indigestion)
* Peripheral [[oedema]]
* [[Dysphagia]]
{{colend}}
* [[Extrapyramidal side effects|Extrapyramidal disease]]: Quetiapine and clozapine are noted for their relative ''lack'' of extrapyramidal side effects.<ref name = Lancet /><ref name = "BNF 65" /><ref name = Maudsley />
* Weight gain: [[Standardised mean difference|SMD]] 0.43&nbsp;kg when compared to placebo. Produces roughly as much weight gain as [[risperidone]], less weight gain than [[clozapine]], [[olanzapine]] and [[zotepine]] and more weight gain than [[ziprasidone]], [[lurasidone]], [[aripiprazole]] and [[asenapine]].<ref name = Lancet /> As with many other atypical antipsychotics, this action is likely due to its actions at the [[Histamine H1 receptor|H<sub>1</sub> histamine receptor]] and [[5-HT2C receptor|5-HT<sub>2C</sub> receptor]].<ref name = GG />

;Rare (<1% incidence) adverse effects
{{Div col|colwidth=30em}}
* Prolonged [[QT interval]] (had an odds ratio for prolonging the QT interval over placebo of 0.17)<ref name = "Lancet" />
* [[Sudden cardiac death]]
* [[Syncope (medicine)|Syncope]]
* [[Diabetic ketoacidosis]]
* [[Restless legs syndrome]]
* [[Hyponatraemia]], low blood sodium.
* [[Jaundice]], yellowing of the eyes, skin and mucous membranes due to an impaired ability of the body to clear bilirubin, a by product of haem breakdown.
* [[Pancreatitis]], pancreas swelling.
* [[Agranulocytosis]], a potentially fatal drop in white blood cell count.
* [[Leukopenia]], a drop in white blood cell count, not as severe as agranulocytosis.
* [[Neutropenia]], a drop in neutrophils, the cell of the immune cells that defends the body against bacterial infections.
* [[Eosinophilia]]
* [[Anaphylaxis]], a potentially fatal allergic reaction.
* [[Seizure]]
* [[Hypothyroidism]], underactive thyroid gland. Common among bipolar patients; quetiapine increases incidence.<ref>{{cite journal | vauthors = Lambert CG, Mazurie AJ, Lauve NR, Hurwitz NG, Young SS, Obenchain RL, Hengartner NW, Perkins DJ, Tohen M, Kerner B | title = Hypothyroidism risk compared among nine common bipolar disorder therapies in a large US cohort | journal = Bipolar Disorders | volume = 18 | issue = 3 | pages = 247–260 | date = May 2016 | pmid = 27226264 | pmc = 5089566 | doi = 10.1111/bdi.12391 }}</ref>
* [[Myocarditis]], swelling of the myocardium.
* [[Cardiomyopathy]]
* [[Hepatitis]], swelling of the liver.
* [[Suicidal ideation]]
* [[Priapism]]. A prolonged and painful erection.
* [[Stevens–Johnson syndrome]]. A potentially fatal skin reaction.
{{colend}}
* [[Neuroleptic malignant syndrome]] a rare and potentially fatal complication of antipsychotic drug treatment. It is characterised by the following symptoms: tremor, rigidity, hyperthermia, tachycardia, mental status changes (e.g. confusion), etc.
* [[Tardive dyskinesia]]. A rare and often irreversible neurological condition characterised by involuntary movements of the face, tongue, lips and rest of the body. Most commonly occurs after prolonged treatment with antipsychotics. It is believed to be particularly uncommon with atypical antipsychotics, especially quetiapine and clozapine<ref name="AMH"/>

Both typical and atypical antipsychotics can cause [[tardive dyskinesia]].<ref name=TD08>{{cite journal | vauthors = Correll CU, Schenk EM | title = Tardive dyskinesia and new antipsychotics | journal = Current Opinion in Psychiatry | volume = 21 | issue = 2 | pages = 151–156 | date = March 2008 | pmid = 18332662 | doi = 10.1097/YCO.0b013e3282f53132 | s2cid = 37288246 }}</ref> According to one study, rates are lower with the atypicals at 3.9% as opposed to the typicals at 5.5%.<ref name=TD08/> Although quetiapine and clozapine are atypical antipsychotics, switching to these atypicals is an option to minimize symptoms of tardive dyskinesia caused by other atypicals.<ref>{{cite journal | vauthors = Aia PG, Revuelta GJ, Cloud LJ, Factor SA | title = Tardive dyskinesia | journal = Current Treatment Options in Neurology | volume = 13 | issue = 3 | pages = 231–241 | date = June 2011 | pmid = 21365202 | doi = 10.1007/s11940-011-0117-x | s2cid = 24308129 }}</ref>

Weight gain can be a problem for some, with quetiapine causing more weight gain than [[fluphenazine]], [[haloperidol]], [[loxapine]], [[molindone]], [[olanzapine]], [[pimozide]], [[risperidone]], [[thioridazine]], [[thiothixene]], [[trifluoperazine]], and [[ziprasidone]], but less than [[chlorpromazine]], [[clozapine]], [[perphenazine]], and [[sertindole]].<ref name="pmid10553730">{{cite journal | vauthors = Allison DB, Mentore JL, Heo M, Chandler LP, Cappelleri JC, Infante MC, Weiden PJ | title = Antipsychotic-induced weight gain: a comprehensive research synthesis | journal = The American Journal of Psychiatry | volume = 156 | issue = 11 | pages = 1686–96 | date = November 1999 | pmid = 10553730 | doi = 10.1176/ajp.156.11.1686 | s2cid = 38635470 }}</ref>

As with some other anti-psychotics, quetiapine may lower the [[seizure threshold]],<ref>{{cite web | url = http://www.astrazeneca-us.com/cgi-bin/az_pi.cgi?product=seroquel&country=us&popup=no | title = Seroquel Prescribing Information | work = www.astrazeneca-us.com | access-date = 21 November 2011 | archive-date = 29 August 2021 | archive-url = https://web.archive.org/web/20210829022950/https://den8dhaj6zs0e.cloudfront.net/50fd68b9-106b-4550-b5d0-12b045f8b184/13735ffe-1301-450c-81c1-683183cea7be/13735ffe-1301-450c-81c1-683183cea7be_viewable_rendition__v.pdf }}</ref> and should be taken with caution in combination with drugs such as [[bupropion]].

===Discontinuation===
The [[British National Formulary]] recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse.<ref name="Group 2009 192">{{cite book | editor = Joint Formulary Committee BMJ | title = British National Formulary | edition = 57 | date = March 2009 |publisher=Royal Pharmaceutical Society of Great Britain |location=United Kingdom |isbn=978-0-85369-845-6 |page=192 |chapter=4.2.1 |quote=Withdrawal of antipsychotic drugs after long-term therapy should always be gradual and closely monitored to avoid the risk of acute withdrawal syndromes or rapid relapse.}}</ref> Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite.<ref name=Had2004>{{cite book | vauthors = Haddad PM, Dursun S, Deakin B |title=Adverse Syndromes and Psychiatric Drugs: A Clinical Guide |date=2004 |publisher=OUP Oxford |isbn=978-0-19-852748-0 |pages=207–216 |url=https://books.google.com/books?id=CWR7DwAAQBAJ&pg=PA207 |language=en}}</ref> Other symptoms may include restlessness, increased sweating, and trouble sleeping.<ref name=Had2004/> Less commonly there may be a feeling of the world spinning, numbness, or muscle pains.<ref name=Had2004/> Symptoms generally resolve after a short period of time.<ref name=Had2004/>

There is tentative evidence that discontinuation of antipsychotics can result in psychosis.<ref>{{cite journal | vauthors = Moncrieff J | title = Does antipsychotic withdrawal provoke psychosis? Review of the literature on rapid onset psychosis (supersensitivity psychosis) and withdrawal-related relapse | journal = Acta Psychiatrica Scandinavica | volume = 114 | issue = 1 | pages = 3–13 | date = July 2006 | pmid = 16774655 | doi = 10.1111/j.1600-0447.2006.00787.x | s2cid = 6267180 }}</ref> It may also result in reoccurrence of the condition that is being treated.<ref>{{cite book | vauthors = Sacchetti E, Vita A, Siracusano A, Fleischhacker W |title=Adherence to Antipsychotics in Schizophrenia |date=2013 |publisher=Springer Science & Business Media |isbn=978-88-470-2679-7 |page=85 |url=https://books.google.com/books?id=odE-AgAAQBAJ&pg=PA85 |language=en}}</ref> Rarely tardive dyskinesia can occur when the medication is stopped.<ref name=Had2004/>

===Pregnancy and lactation===
Placental exposure is least for quetiapine compared to other atypical antipsychotics.<ref name = Maudsley/> The evidence is insufficient to rule out any risk to the foetus but available data suggests it is unlikely to result in any major foetal malformations.<ref name = EMC/><ref name = DM/><ref name = TGA/> It is secreted in breast milk and hence quetiapine-treated mothers are advised not to breastfeed.<ref name = EMC/><ref name = DM/><ref name = TGA/>

===Abuse potential===
In contrast to most other antipsychotic drugs, which tend to be somewhat aversive and often show problems with patient compliance with prescribed medication regimes, quetiapine is sometimes associated with [[Substance abuse|drug misuse]] and abuse potential, for its hypnotic and sedative effects. It has a limited potential for misuse, usually only in individuals with a history of polysubstance abuse and/or mental illness, and especially in those incarcerated in prisons or secure psychiatric facilities where access to alternative intoxicants is more limited. To a significantly greater extent than other atypical antipsychotic drugs, quetiapine was found to be associated with drug-seeking behaviors, and to have standardised street prices and slang terms associated with it, either by itself or in combination with other drugs (such as "Q-ball" for the intravenous injection of quetiapine mixed with [[cocaine]]). The pharmacological basis for this distinction from other second generation antipsychotic drugs is unclear, though it has been suggested that quetiapine's comparatively lower dopamine receptor affinity and strong antihistamine activity might mean it could be regarded as more similar to sedating [[antihistamine]]s in this context. While these issues have not been regarded as sufficient cause for placing quetiapine under increased legal controls, prescribers have been urged to show caution when prescribing quetiapine to individuals with characteristics that might place them at increased risk for drug misuse.<ref>{{cite journal | vauthors = Klein L, Bangh S, Cole JB | title = Intentional Recreational Abuse of Quetiapine Compared to Other Second-generation Antipsychotics | journal = The Western Journal of Emergency Medicine | volume = 18 | issue = 2 | pages = 243–250 | date = February 2017 | pmid = 28210359 | pmc = 5305132 | doi = 10.5811/westjem.2016.10.32322 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Kim S, Lee G, Kim E, Jung H, Chang J | title = Quetiapine Misuse and Abuse: Is it an Atypical Paradigm of Drug Seeking Behavior? | journal = Journal of Research in Pharmacy Practice | volume = 6 | issue = 1 | pages = 12–15 | year = 2017 | pmid = 28331860 | pmc = 5348850 | doi = 10.4103/2279-042X.200987 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Chiappini S, Schifano F | title = Is There a Potential of Misuse for Quetiapine?: Literature Review and Analysis of the European Medicines Agency/European Medicines Agency Adverse Drug Reactions' Database | journal = Journal of Clinical Psychopharmacology | volume = 38 | issue = 1 | pages = 72–79 | date = February 2018 | pmid = 29210868 | doi = 10.1097/JCP.0000000000000814 | hdl-access = free | s2cid = 3292900 | hdl = 2299/19835 }}</ref><ref>{{cite journal | vauthors = Evoy KE, Teng C, Encarnacion VG, Frescas B, Hakim J, Saklad S, Frei CR | title = Comparison of Quetiapine Abuse and Misuse Reports to the FDA Adverse Event Reporting System With Other Second-Generation Antipsychotics | journal = Substance Abuse | volume = 13 | article-number = 1178221819844205 | year = 2019 | pmid = 31068753 | pmc = 6495438 | doi = 10.1177/1178221819844205 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Vento AE, Kotzalidis GD, Cacciotti M, Papanti GD, Orsolini L, Rapinesi C, Savoja V, Calabrò G, Del Casale A, Piacentino D, Caloro M, Girardi P, Schifano F | title = Quetiapine Abuse Fourteen Years Later: Where Are We Now? A Systematic Review | journal = Substance Use & Misuse | volume = 55 | issue = 2 | pages = 304–313 | year = 2020 | pmid = 31573374 | doi = 10.1080/10826084.2019.1668013 | s2cid = 203621793 }}</ref>

==Overdose==
Most instances of acute overdosage result in only sedation, hypotension and tachycardia, but cardiac arrhythmia, coma and death have occurred in adults. Serum or plasma quetiapine concentrations are usually in the 1–10&nbsp;mg/L range in overdose survivors, while postmortem blood levels of 10–25&nbsp;mg/L are generally observed in fatal cases.<ref>{{cite book | vauthors = Baselt R | title = Disposition of Toxic Drugs and Chemicals in Man | edition = 8th | publisher = Biomedical Publications | location = Foster City, CA | date = 2008 | pages = 1355–1357 }}</ref> Non-toxic levels in postmortem blood extend to around 0.8&nbsp;mg/kg, but toxic levels in postmortem blood can begin at 0.35&nbsp;mg/kg.<ref name="Skov 2015 41-44">{{cite journal | vauthors = Skov L, Johansen SS, Linnet K | title = Postmortem femoral blood reference concentrations of aripiprazole, chlorprothixene, and quetiapine | journal = Journal of Analytical Toxicology | volume = 39 | issue = 1 | pages = 41–44 | date = Jan 2015 | pmid = 25342720 | doi = 10.1093/jat/bku121 | doi-access = free }}</ref><ref name="Skov 2015 557-561">{{cite journal | vauthors = Skov L, Johansen SS, Linnet K | title = Postmortem Quetiapine Reference Concentrations in Brain and Blood | journal = Journal of Analytical Toxicology | volume = 39 | issue = 7 | pages = 557–561 | date = September 2015 | pmid = 26159868 | doi = 10.1093/jat/bkv072 | doi-access = free }}</ref>

==Pharmacology==

===Pharmacodynamics===
{{See also|Atypical antipsychotic#Pharmacodynamics|Antipsychotic#Comparison of medications}}
{| class="wikitable floatright" style="font-size:small;"
|+ Quetiapine (and metabolite)<ref name="PDSP">{{cite web | title = PDSP K<sub>i</sub> Database | website = Psychoactive Drug Screening Program (PDSP) | vauthors = Roth BL, Driscol J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://pdsp.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testLigandDD=&testFreeRadio=testFreeRadio&testLigand=quetiapine&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref><ref name="pmid18059438" />
|-
! Site !! {{abbr|QTP|Quetiapine}} !! {{abbr|NQTP|Norquetiapine}} !! Action !! Ref
|-
| {{abbrlink|SERT|Serotonin transporter}} || >10,000 || 927 || Blocker || <ref name="pmid18059438">{{cite journal | vauthors = Jensen NH, Rodriguiz RM, Caron MG, Wetsel WC, Rothman RB, Roth BL | title = N-desalkylquetiapine, a potent norepinephrine reuptake inhibitor and partial 5-HT1A agonist, as a putative mediator of quetiapine's antidepressant activity | journal = Neuropsychopharmacology | volume = 33 | issue = 10 | pages = 2303–2312 | date = September 2008 | pmid = 18059438 | doi = 10.1038/sj.npp.1301646 | doi-access = free | author6-link = Bryan Roth }}</ref>
|-
| {{abbrlink|NET|Norepinephrine transporter}} || >10,000 || 58 || Blocker || <ref name="pmid18059438" />
|-
| {{abbrlink|DAT|Dopamine transporter}} || >10,000 || >10,000 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[5-HT1A receptor|5-HT<sub>1A</sub>]] || 320–432 || 45 || Partial agonist || <ref name="pmid18059438" /><ref name="pmid8935801">{{cite journal | vauthors = Schotte A, Janssen PF, Gommeren W, Luyten WH, Van Gompel P, Lesage AS, De Loore K, Leysen JE | title = Risperidone compared with new and reference antipsychotic drugs: in vitro and in vivo receptor binding | journal = Psychopharmacology | volume = 124 | issue = 1–2 | pages = 57–73 | date = March 1996 | pmid = 8935801 | doi = 10.1007/bf02245606 | s2cid = 12028979 }}</ref>
|-
| [[5-HT1B receptor|5-HT<sub>1B</sub>]] || 1,109–2,050 || 1,117 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[5-HT1D receptor|5-HT<sub>1D</sub>]] || >10,000 || 249 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[5-HT1E receptor|5-HT<sub>1E</sub>]] || 1,250–2,402 || 97 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[5-HT1F receptor|5-HT<sub>1F</sub>]] || 2,240 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || <ref name="pmid8935801" />
|-
| [[5-HT2A receptor|5-HT<sub>2A</sub>]] || 96–101 || 48 || Antagonist || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[5-HT2B receptor|5-HT<sub>2B</sub>]] || {{abbr|ND|No data}} || 14 || Antagonist || <ref name="pmid18059438" />
|-
| [[5-HT2C receptor|5-HT<sub>2C</sub>]] || 2,502 || 107 || Antagonist || <ref name="pmid18059438" />
|-
| [[5-HT3 receptor|5-HT<sub>3</sub>]] || >10,000 || 394 || Antagonist || <ref name="pmid18059438" />
|-
| [[5-HT4 receptor|5-HT<sub>4</sub>]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}}
|-
| [[5-HT5A receptor|5-HT<sub>5A</sub>]] || 3,120 || 768 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[5-HT6 receptor|5-HT<sub>6</sub>]] || 1,865 || 503 || Antagonist || <ref name="pmid18059438" />
|-
| [[5-HT7 receptor|5-HT<sub>7</sub>]] || 307 || 76 || Antagonist || <ref name="pmid18059438" />
|-
| [[Alpha-1A adrenergic receptor|α<sub>1A</sub>]] || 22 || 144 || Antagonist || <ref name="pmid18059438" />
|-
| [[Alpha-1B adrenergic receptor|α<sub>1B</sub>]] || 39 || 95 || Antagonist || <ref name="pmid18059438" />
|-
| [[Alpha-2A adrenergic receptor|α<sub>2A</sub>]] || 2,230–3,630 || 237 || Antagonist || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Alpha-2B adrenergic receptor|α<sub>2B</sub>]] || 90–747 || 378 || Antagonist || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Alpha-2C adrenergic receptor|α<sub>2C</sub>]] || 28.7–350 || 736 || Antagonist || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Beta-1 adrenergic receptor|β<sub>1</sub>]] || >10,000 || >10,000 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Beta-2 adrenergic receptor|β<sub>2</sub>]] || >10,000 || >10,000 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Dopamine D1 receptor|D<sub>1</sub>]] || 712 || 214 || Antagonist || <ref name="pmid18059438" />
|-
| [[Dopamine D2 receptor|D<sub>2</sub>]] || 245 || 196 || Antagonist || <ref name="pmid18059438" />
|-
| [[Dopamine D2 receptor|D<sub>2L</sub>]] || 700 || {{abbr|ND|No data}} || Antagonist || <ref name="pmid8935801" />
|-
| [[Dopamine D2 receptor|D<sub>2S</sub>]] || 390 || {{abbr|ND|No data}} || Antagonist || <ref name="pmid8935801" />
|-
| [[Dopamine D3 receptor|D<sub>3</sub>]] || 340–483 || 567 || Antagonist || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Dopamine D4 receptor|D<sub>4</sub>]] || 1,202 || 1,297 || Antagonist || <ref name="pmid18059438" />
|-
| [[Dopamine D4 receptor|D<sub>4.2</sub>]] || 1,600 || {{abbr|ND|No data}} || Antagonist || <ref name="pmid8935801" />
|-
| [[Dopamine D5 receptor|D<sub>5</sub>]] || 1,738 || 1,419 || Antagonist || <ref name="pmid18059438" />
|-
| [[Histamine H1 receptor|H<sub>1</sub>]] || 2.2–11 || 3.5 || Antagonist || <ref name="pmid18059438" />
|-
| [[Histamine H2 receptor|H<sub>2</sub>]] || >10,000 || 298 || Antagonist || <ref name="pmid18059438" />
|-
| [[Histamine H3 receptor|H<sub>3</sub>]] || >10,000 || >10,000 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[Histamine H4 receptor|H<sub>4</sub>]] || >10,000 || 1,660 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[Muscarinic acetylcholine receptor M1|M<sub>1</sub>]] || 858 || 39 || Antagonist || <ref name="pmid18059438" />
|-
| [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] || 1,339 || 453 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[Muscarinic acetylcholine receptor M3|M<sub>3</sub>]] || >10,000 || 23 || Antagonist || <ref name="pmid18059438" />
|-
| [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] || 542 || 110 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[Muscarinic acetylcholine receptor M5|M<sub>5</sub>]] || 1,942 || 23 || Antagonist || <ref name="pmid18059438" />
|-
| [[Sigma-1 receptor|σ<sub>1</sub>]] || 220–3,651 || >10,000 || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| [[Sigma-2 receptor|σ<sub>2</sub>]] || 1,344 || 1,050 || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|-
| [[NMDA receptor|{{abbr|NMDA|N-Methyl-D-aspartate receptor}}<br />({{abbr|PCP|Phencyclidine site}})]] || >10,000 || {{abbr|ND|No data}} || Antagonist || <ref name="pmid18059438" />
|-
| {{abbrlink|VDCC|Voltage-dependent calcium channel}} || >10,000 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || <ref name="pmid18059438" /><ref name="pmid8935801" />
|-
| {{abbrlink|hERG|Human Ether-à-go-go-Related Gene}} || {{abbr|ND|No data}} || >10,000<br />({{abbrlink|IC<sub>50</sub>|Half-maximal inhibitory concentration}}) || {{abbr|ND|No data}} || <ref name="pmid18059438" />
|- class="sortbottom"
| colspan="5" style="width: 1px;" | Values are K<sub>i</sub> (nM), unless otherwise noted. The smaller the value, the more strongly the drug binds to the site. All data are for human cloned proteins, except σ<sub>1</sub> (guinea pig), σ<sub>2</sub> (rat), and {{abbr|VDCC|Voltage-dependent calcium channel}} (rat).<ref name="pmid18059438" /><ref name="pmid8935801" />
|}

Quetiapine has the following pharmacological actions:<ref name=Seroquel>{{cite web |publisher=[[AstraZeneca]] |id=276521 |title=Seroquel (quietapine fumarate) tablets |url=http://www1.astrazeneca-us.com/pi/Seroquel.pdf |archive-url=https://web.archive.org/web/20080414031803/http://www1.astrazeneca-us.com/pi/Seroquel.pdf |archive-date=14 April 2008 }}</ref><ref name="pmid11132243">{{cite journal | vauthors = Richelson E, Souder T | title = Binding of antipsychotic drugs to human brain receptors focus on newer generation compounds | journal = Life Sciences | volume = 68 | issue = 1 | pages = 29–39 | date = November 2000 | pmid = 11132243 | doi = 10.1016/S0024-3205(00)00911-5 }}</ref><ref name="urlNeuropsychopharmacology: the fifth ... - Google Books">{{cite book | chapter-url = https://books.google.com/books?id=BKwkonZwZD0C&pg=PA778 | vauthors = Miyamoto SE, Duncan GE, Goff DC, Lieberman JA | chapter = Therapeutics of schizophrenia | title = Neuropsychopharmacology: the fifth generation of progress | isbn = 978-0-7817-2837-9 | veditors = Davis KL, Charney D, Coyle JT, Nemeroff C | publisher = American College of Neuropsychopharmacology | year = 2002 }}</ref><ref>{{cite web |url=https://www.drugs.com/pro/seroquel.html |title=Seroquel Official FDA information, side effects and uses |publisher=Drugs.com |access-date=9 July 2012 |url-status = live|archive-url=https://web.archive.org/web/20120604005526/http://www.drugs.com/pro/seroquel.html |archive-date=4 June 2012 }}</ref><ref name="dailymed PI">{{cite web | title=Seroquel- quetiapine tablet, film coated | website=DailyMed | date=27 January 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0584dda8-bc3c-48fe-1a90-79608f78e8a0 | access-date=22 September 2024}}</ref><ref>National Institute of Mental Health. PDSD Ki Database (Internet) [cited 2013 Sep 18]. Chapel Hill (NC): University of North Carolina. 1998-2013. Available from: {{cite web|url=http://pdsp.med.unc.edu/pdsp.php |title=...list shows the top 100 Receptors/Targets in Ki|access-date=5 July 2013 |archive-url=https://web.archive.org/web/20131108013656/http://pdsp.med.unc.edu/pdsp.php |archive-date=8 November 2013 }}</ref><ref>{{cite journal | vauthors = Jensen NH, Rodriguiz RM, Caron MG, Wetsel WC, Rothman RB, Roth BL | title = N-desalkylquetiapine, a potent norepinephrine reuptake inhibitor and partial 5-HT1A agonist, as a putative mediator of quetiapine's antidepressant activity | journal = Neuropsychopharmacology | volume = 33 | issue = 10 | pages = 2303–2312 | date = September 2008 | pmid = 18059438 | doi = 10.1038/sj.npp.1301646 | doi-access = free }}</ref><ref>{{cite journal | vauthors = López-Muñoz F, Alamo C | title = Active metabolites as antidepressant drugs: the role of norquetiapine in the mechanism of action of quetiapine in the treatment of mood disorders | journal = Frontiers in Psychiatry | volume = 4 | page = 102 | date = September 2013 | pmid = 24062697 | pmc = 3770982 | doi = 10.3389/fpsyt.2013.00102 | doi-access = free }}</ref>

* [[Dopamine receptor|Dopamine]] [[D1 receptor|D<sub>1</sub>]], [[D2 receptor|D<sub>2</sub>]], [[D3 receptor|D<sub>3</sub>]], [[D4 receptor|D<sub>4</sub>]], and [[D5 receptor|D<sub>5</sub> receptor]] [[dopamine receptor antagonist|antagonist]]
* [[Serotonin receptor|Serotonin]] [[5-HT1A receptor|5-HT<sub>1A</sub> receptor]] [[partial agonist]], [[5-HT2A receptor|5-HT<sub>2A</sub>]], [[5-HT2B receptor|5-HT<sub>2B</sub>]], [[5-HT2C receptor|5-HT<sub>2C</sub>]], [[5-HT3 receptor|5-HT<sub>3</sub>]], [[5-HT6 receptor|5-HT<sub>6</sub>]], and [[5-HT7 receptor|5-HT<sub>7</sub> receptor]] [[serotonin receptor antagonist|antagonist]], and [[5-HT1B receptor|5-HT<sub>1B</sub>]], [[5-HT1D receptor|5-HT<sub>1D</sub>]], [[5-HT1E receptor|5-HT<sub>1E</sub>]], and [[5-HT1F receptor|5-HT<sub>1F</sub> receptor]] [[ligand (biochemistry)|ligand]]
* [[alpha-1 adrenergic receptor|α<sub>1</sub>-]] and [[alpha-2 adrenergic receptor|α<sub>2</sub>-adrenergic receptor]] [[alpha blocker|antagonist]]
* [[Histamine receptor|Histamine]] [[H1 receptor|H<sub>1</sub> receptor]] [[antihistamine|antagonist]]
* [[Muscarinic acetylcholine receptor]] [[antimuscarinic|antagonist]]

This means quetiapine is a [[dopamine antagonist|dopamine]], [[serotonin antagonist|serotonin]], and [[adrenergic antagonist|adrenergic]] antagonist, and a potent [[antihistamine]] with some [[anticholinergic]] properties.<ref>{{cite journal | vauthors = Chew ML, Mulsant BH, Pollock BG, Lehman ME, Greenspan A, Mahmoud RA, Kirshner MA, Sorisio DA, Bies RR, Gharabawi G | title = Anticholinergic activity of 107 medications commonly used by older adults | journal = Journal of the American Geriatrics Society | volume = 56 | issue = 7 | pages = 1333–1341 | date = July 2008 | pmid = 18510583 | doi = 10.1111/j.1532-5415.2008.01737.x | s2cid = 11448976 }}</ref> Quetiapine binds strongly to serotonin receptors; the drug acts as a [[partial agonist]] at 5-HT<sub>1A</sub> receptors and as an antagonist to all other serotonin receptors it has affinity for.<ref>{{cite web | vauthors = Guzman F |title=Mechanism of action of quetiapine |url= http://psychopharmacologyinstitute.com/antipsychotics/quetiapine/mechanism-of-action/|publisher=Psychopharmacology Institute |access-date=20 January 2013 |url-status = live |archive-url= https://web.archive.org/web/20130811004624/http://psychopharmacologyinstitute.com/antipsychotics/quetiapine/mechanism-of-action/ |archive-date=11 August 2013 }}</ref> Serial PET scans evaluating the D<sub>2</sub> receptor occupancy of quetiapine have demonstrated that quetiapine very rapidly disassociates from the D<sub>2</sub> receptor.<ref>{{cite journal | vauthors = Kapur S, Seeman P | title = Does fast dissociation from the dopamine d(2) receptor explain the action of atypical antipsychotics?: A new hypothesis | journal = The American Journal of Psychiatry | volume = 158 | issue = 3 | pages = 360–369 | date = March 2001 | pmid = 11229973 | doi = 10.1176/appi.ajp.158.3.360 }}</ref> Theoretically, this allows for normal physiological surges of dopamine to elicit normal effects in areas such as the [[nigrostriatal]] and [[tuberoinfundibular]] pathways, thus minimizing the risk of side-effects such as pseudo-parkinsonism as well as elevations in [[prolactin]].<ref>{{cite journal | vauthors = Seeman P | title = Atypical antipsychotics: mechanism of action | journal = Canadian Journal of Psychiatry. Revue Canadienne de Psychiatrie | volume = 47 | issue = 1 | pages = 27–38 | date = February 2002 | pmid = 11873706 | doi = 10.1177/070674370204700106 | doi-access = free }}</ref> Some of the antagonized receptors (serotonin, norepinephrine) are actually [[autoreceptor]]s whose blockade tends to increase the release of neurotransmitters.

At very low doses, quetiapine acts primarily as a histamine receptor blocker (antihistamine) and [[alpha-1 adrenergic receptor|α<sub>1</sub>-adrenergic]] blocker. When the dose is increased, quetiapine activates the adrenergic system and binds strongly to serotonin receptors and [[autoreceptor]]s. At high doses, quetiapine starts blocking significant amounts of dopamine receptors.<ref name="pmid11132243"/><ref>{{cite journal | vauthors = Gefvert O, Lundberg T, Wieselgren IM, Bergström M, Långström B, Wiesel F, Lindström L | title = D(2) and 5HT(2A) receptor occupancy of different doses of quetiapine in schizophrenia: a PET study | journal = European Neuropsychopharmacology | volume = 11 | issue = 2 | pages = 105–110 | date = April 2001 | pmid = 11313155 | doi = 10.1016/S0924-977X(00)00133-4 | s2cid = 29460397 }}</ref> Due to the drug's sedating H<sub>1</sub> activity, it is often prescribed at low doses for insomnia. While some feel that low doses of drugs with antihistamine effects like quetiapine and [[mirtazapine]] are safer than drugs associated with physical dependency or other risk factors, concern has been raised by some professionals that off-label prescribing has become too widespread due to underappreciated hazards.<ref name="low_dose">{{cite web|title=Drug Use Evaluation: Low Dose Quetiapine (Seroquel/Seroquel XR)|url=http://www.govexec.com/pdfs/013111bb1a.pdf|website=Government Executive Media Group|publisher=Oregon State|access-date=20 January 2016|url-status = live|archive-url=https://web.archive.org/web/20160422184014/http://www.govexec.com/pdfs/013111bb1a.pdf|archive-date=22 April 2016}}</ref>

When treating schizophrenia, antagonism of D<sub>2</sub> receptor by quetiapine in the mesolimbic pathway relieves positive symptoms and antagonism of the 5-HT<sub>2A</sub> receptor in the frontal cortex of the brain may relieve negative symptoms and reduce severity of psychotic episodes.<ref name="Quetiapine"/><ref name="drugbank.ca">{{cite web |title=Quetiapine |url=https://www.drugbank.ca/drugs/DB01224 |website=www.drugbank.ca |access-date=23 January 2019}}</ref><ref>{{cite web |title=Seroquel |url=https://www.accessdata.fda.gov/drugsatfda_docs/label/2004/20639se1-017,016_seroquel_lbl.pdf |archive-url=https://web.archive.org/web/20110214113134/http://www.accessdata.fda.gov/drugsatfda_docs/label/2004/20639se1-017,016_seroquel_lbl.pdf |archive-date=14 February 2011 |website=FDA |access-date=23 January 2019}}</ref> Quetiapine has fewer extrapyramidal side effects and is less likely to cause hyperprolactinemia when compared to other drugs used to treat schizophrenia, so is used as a first line treatment.<ref>{{cite journal | vauthors = Nemeroff CB, Kinkead B, Goldstein J | title = Quetiapine: preclinical studies, pharmacokinetics, drug interactions, and dosing | journal = The Journal of Clinical Psychiatry | volume = 63 | issue = Suppl 13 | pages = 5–11 | date = 2002 | pmid = 12562141 }}</ref><ref>{{cite journal | vauthors = Kasper S, Müller-Spahn F | title = Review of quetiapine and its clinical applications in schizophrenia | journal = Expert Opinion on Pharmacotherapy | volume = 1 | issue = 4 | pages = 783–801 | date = May 2000 | pmid = 11249516 | doi = 10.1517/14656566.1.4.783 | s2cid = 22978385 }}</ref>

Since the noradrenaline transporter is responsible for most of the dopamine clearance in the prefrontal cortex, norquetiapine blocks reuptake of dopamine too, accumulating the dopamine in the synapse.<ref>{{cite journal | title=Dopamine Uptake through the Norepinephrine Transporter in Brain Regions with Low Levels of the Dopamine Transporter: Evidence from Knock-Out Mouse Lines | journal=The Journal of Neuroscience | date=2002 | volume=22 | issue=2 | pages=389–395 | doi=10.1523/JNEUROSCI.22-02-00389.2002 | pmid=11784783 | pmc=6758674 | vauthors = Morón JA, Brockington A, Wise RA, Rocha BA, Hope BT }}</ref>

===Pharmacokinetics===
Peak levels of quetiapine occur 1.5&nbsp;hours after a dose.<ref name="SeroquelLabel" /> The [[plasma protein binding]] of quetiapine is 83%.<ref name="SeroquelLabel" /> The major [[active metabolite]] of quetiapine is [[norquetiapine]] (''N''-desalkylquetiapine).<ref name="pmid18059438" /> Quetiapine has an [[elimination half-life]] of 6 or 7&nbsp;hours.<ref name="SeroquelLabel" /><ref name="EMC" /><ref name="DD" /> Its metabolite, norquetiapine, has a half-life of 9 to 12&nbsp;hours.<ref name="EMC" /><ref name="DD" /> Quetiapine is [[excretion|excreted]] primarily via the [[kidney]]s (73%) and in [[feces]] (20%) after hepatic metabolism, the remainder (1%) is excreted as the drug in its unmetabolized form.<ref name="drugbank.ca"/><ref name="SeroquelLabel">{{cite web |title=Seroquel |url=https://www.accessdata.fda.gov/drugsatfda_docs/label/2004/20639se1-017,016_seroquel_lbl.pdf |archive-url=https://web.archive.org/web/20110214113134/http://www.accessdata.fda.gov/drugsatfda_docs/label/2004/20639se1-017,016_seroquel_lbl.pdf |archive-date=14 February 2011 |website=FDA |access-date=23 January 2019}}</ref>

[[File:Norquetiapine.svg|class=skin-invert-image|left|thumb|200px|Skeletal formula of norquetiapine]] {{Clear left}}

==Chemistry==
Quetiapine is a [[tetracyclic compound]] and is closely related structurally to [[clozapine]], [[olanzapine]], [[loxapine]], and other tetracyclic antipsychotics.

===Synthesis===
The synthesis of quetiapine begins with a dibenzothiazepinone. The [[lactam]] is first treated with [[phosphoryl chloride]] to produce a [[dibenzothiazepine]]. A [[nucleophilic substitution]] is used to introduce the sidechain.<ref>Warawa, E. J.; Migler, B. M.; 1988, {{US Patent|4879288}}.</ref>

[[File:Quetiapine syn.png|class=skin-invert-image|center|600px]]

==History==

===Sustained-release===
[[AstraZeneca]] submitted a [[new drug application]] for a [[sustained-release]] version of quetiapine in the United States, Canada, and the European Union in the second half of 2006 for treatment of schizophrenia.<ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/pressrelease/5256.aspx|title=AstraZeneca Submits an NDA For Sustained Release Formulation Seroquel XR. For the treatment of schizophrenia.|date=18 July 2006|access-date=1 January 2007|url-status = live|archive-url=https://web.archive.org/web/20061105230337/http://www.astrazeneca.com/pressrelease/5256.aspx|archive-date=5 November 2006}}</ref><ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/pressrelease/5275.aspx|title=AstraZeneca Submits EU and Canadian Regulatory Filings for Sustained Release Formulation Seroquel XR for the Treatment of Schizophrenia|date=19 October 2006|access-date=1 January 2007|url-status = live|archive-url=https://web.archive.org/web/20061107132140/http://www.astrazeneca.com/pressrelease/5275.aspx|archive-date=7 November 2006}}</ref>

In May 2007, the US FDA approved Seroquel XR for acute treatment of schizophrenia.<ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/pressrelease/5330.aspx|title=FDA Approves AstraZeneca's Once-Daily Seroquel Xr Extended-Release Tablets For The Treatment Of Schizophrenia|date=18 May 2007|access-date=2 August 2007|url-status = live|archive-url=https://web.archive.org/web/20070928040539/http://www.astrazeneca.com/pressrelease/5330.aspx|archive-date=28 September 2007}}</ref> During its 2007 Q2 earnings conference, AstraZeneca announced plans to launch Seroquel XR in the U.S. during August 2007.<ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/pressrelease/5341.aspx|title=Second Quarter and Half Year Results 2007|date=26 July 2007|access-date=2 August 2007|url-status = live|archive-url=https://web.archive.org/web/20070824192553/http://www.astrazeneca.com/pressrelease/5341.aspx|archive-date=24 August 2007}}</ref> However, Seroquel XR has become available in U.S. pharmacies only after the FDA approved Seroquel XR for use as maintenance treatment for schizophrenia, in addition to acute treatment of the illness, on 16 November 2007.<ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/pressrelease/5360.aspx|title=Seroquel XR Receives Approval from FDA for Maintenance Treatment of Schizophrenia|date=16 November 2007|access-date=3 December 2007|url-status = live|archive-url=https://web.archive.org/web/20071204160258/http://www.astrazeneca.com/pressrelease/5360.aspx|archive-date=4 December 2007}}</ref> The company has not provided a reason for the delay of Seroquel XR's launch.

[[Health Canada]] approved sale of Seroquel XR on 27 September 2007.<ref>[http://cpe0013211b4c6d-cm0014e88ee7a4.cpe.net.cable.rogers.com/NocWeb/viewnoce.jsp?noc=kilh Notice of Compliance Information - Seroquel XR]{{dead link|date=July 2016 |bot=InternetArchiveBot |fix-attempted=yes }} 27 September 2007, retrieved 3 December 2007</ref>

In October 2008, the FDA approved Seroquel XR for the treatment of bipolar depression and bipolar mania.

In December 2008, [[Biovail]] announced that the FDA had accepted the company's ANDA to market its own version of sustained-release quetiapine.<ref>{{cite press release|publisher=[[Biovail]]|url=http://www.biovail.com/english/Investor%20Relations/Latest%20News/default.asp?s=1&state=showrelease&releaseid=1230930|title=Biovail Announces Filing of ANDA for Quetiapine XR Tablets|date=1 December 2008|archive-url=https://web.archive.org/web/20070809023828/http://www.biovail.com/english/investor%20relations/latest%20news/default.asp?s=1|archive-date=9 August 2007}}</ref> Biovail's sustained-release tablets will compete with AstraZeneca's Seroquel XR.

In December 2008, AstraZeneca notified shareholders that the FDA had asked for additional information on the company's application to expand the use of sustained-release quetiapine for treatment of depression.<ref>{{cite press release|publisher=[[AstraZeneca]]|url=http://www.astrazeneca.com/media/latest-press-releases/seroquel-MDD-FDA-response?itemId=4477598|title=AstraZeneca Receives FDA Complete Response Letter on Seroquel XR for Major Depressive Disorder|date=24 December 2008|access-date=28 December 2008|url-status = live|archive-url=https://web.archive.org/web/20101026190741/http://www.astrazeneca.com/media/latest-press-releases/seroquel-MDD-FDA-response?itemId=4477598|archive-date=26 October 2010}}</ref>

==Society and culture==

===Regulatory status===
In the United States, the [[Food and Drug Administration]] (FDA) has approved quetiapine for the treatment of [[schizophrenia]] and of acute [[mania|manic]] episodes associated with [[bipolar disorder]] ([[Bipolar disorder#Manic episodes|bipolar mania]]) and for treatment of [[Bipolar disorder#Depressive episodes|bipolar depression]].<ref name="Off-label">{{cite web | url = http://www.justice.gov/opa/pr/2010/April/10-civ-487.html | title = Pharmaceutical Giant AstraZeneca to Pay $520 Million for Off-label Drug Marketing | publisher = Justice news, US Department of Justice | access-date = 16 July 2012 |url-status = live| archive-url = https://web.archive.org/web/20120713201923/http://www.justice.gov/opa/pr/2010/April/10-civ-487.html | archive-date = 13 July 2012 | date = 27 April 2010 }}</ref> In 2009, quetiapine XR was approved as adjunctive treatment of major depressive disorder.<ref>{{cite web| vauthors = Guzman F |title=Quetiapine Indications: FDA-Approved and Off-label Uses |url= http://psychopharmacologyinstitute.com/antipsychotics/quetiapine/quetiapine-indications/|publisher=Psychopharmacology Institute |access-date=19 January 2013 |url-status = live |archive-url= https://web.archive.org/web/20140122132819/http://psychopharmacologyinstitute.com/antipsychotics/quetiapine/quetiapine-indications/ |archive-date=22 January 2014 }}</ref>

Quetiapine received its initial approval from the US FDA for the treatment of schizophrenia in 1997.<ref name="dailymed PI" /><ref>{{cite web|title=QUETIAPINE FUMARATE|website=Electronic Orange Book|publisher=Food and Drug Administration|date=April 2007|url=http://www.accessdata.fda.gov/scripts/cder/ob/docs/obdetail.cfm?Appl_No=020639&TABLE1=OB_Rx|access-date=24 May 2007|archive-url=https://web.archive.org/web/20090105000412/http://www.accessdata.fda.gov/scripts/cder/ob/docs/obdetail.cfm?Appl_No=020639&TABLE1=OB_Rx|archive-date=5 January 2009}}</ref> In 2004, it received its second indication for the treatment of mania-associated bipolar disorder.<ref>{{cite press release| publisher=[[AstraZeneca]]| date=13 January 2004| title=AstraZeneca Receives FDA Approval for SEROQUEL in Bipolar Mania| url=http://www.prnewswire.co.uk/cgi/news/release?id=115109 |url-status = live| archive-url= https://web.archive.org/web/20110608181218/http://www.prnewswire.co.uk/cgi/news/release?id=115109| archive-date=8 June 2011}}</ref> In 2007 and 2008, studies were conducted on quetiapine's efficacy in treating generalized anxiety disorder and major depression.

Patent protection for the product ended in 2012; however, in a number of regions, the long-acting version remained under patent until 2017.<ref>{{cite web|author1=AstraZeneca|title=Pioneering science, life-changing medicines |url= https://www.sec.gov/Archives/edgar/data/901832/000095010314001994/dp44853_ex1501.htm |website=www.sec.gov| access-date=26 March 2017|date=2013|url-status = live |archive-url=https://web.archive.org/web/20160306213537/http://www.sec.gov/Archives/edgar/data/901832/000095010314001994/dp44853_ex1501.htm |archive-date=6 March 2016 }}</ref>

===Lawsuits===
In April 2010, the U. S. Department of Justice fined AstraZeneca $520 million for the company's aggressive marketing of Seroquel for [[off-label use]]s.<ref name="Off-label"/> According to the Department of Justice, "the company recruited doctors to serve as authors of articles that were ghostwritten by medical literature companies and about studies the doctors in question did not conduct. AstraZeneca then used those studies and articles as the basis for promotional messages about unapproved uses of Seroquel."<ref name="Off-label"/>

Multiple lawsuits have been filed in relation to quetiapine's side-effects, in particular, [[diabetes]].<ref>{{cite news| url=http://www.madisonrecord.com/news/198781-seroquel-suit-claims-so-much-is-poured-into-marketing-and-away-from-research| title=Seroquel suit claims 'so much' is poured into marketing and away from research| work=[[The Madison / St. Clair Record]]| vauthors = Knef A | date=2 August 2007|url-status = live| archive-url=https://web.archive.org/web/20080821141631/http://www.madisonrecord.com/news/198781-seroquel-suit-claims-so-much-is-poured-into-marketing-and-away-from-research| archive-date=21 August 2008}}</ref><ref name="BloombergNewsSeroquelDiabetes">{{cite news| vauthors = Milford P | date=11 March 2009| work=Bloomberg.com| publisher=[[Bloomberg L.P.]]| url=https://www.bloomberg.com/apps/news?pid=newsarchive&sid=ayzJsK2HlF6s| title=AstraZeneca May Link Seroquel, Diabetes, Doctor Says|url-status = live| archive-url=https://web.archive.org/web/20150924191537/http://www.bloomberg.com/apps/news?pid=newsarchive&sid=ayzJsK2HlF6s| archive-date=24 September 2015}}</ref><ref>{{cite web |url=http://www.fiercepharma.com/story/astrazeneca-wins-bellwether-seroquel-case/2010-03-19 |title=AstraZeneca wins bellwether Seroquel case |publisher=FiercePharma |date=19 March 2010 |access-date=9 July 2012 |url-status = live|archive-url=https://web.archive.org/web/20120314034519/http://www.fiercepharma.com/story/astrazeneca-wins-bellwether-seroquel-case/2010-03-19 |archive-date=14 March 2012 }}</ref><ref>{{cite news|url=http://www.thelocal.se/28260/20100809/|title=AstraZeneca pays out million dollar damages|work=[[The Local]]|date=9 August 2010|url-status = live|archive-url=https://web.archive.org/web/20100817204556/http://www.thelocal.se/28260/20100809/|archive-date=17 August 2010}}</ref>

Approximately 10,000<ref>{{cite news |url=http://www.marinecorpstimes.com/news/2010/08/ap-veterans-affairs-investigation-into-seroquel-083010/ |title=Questions loom over drug for sleepless vets - Marine Corps News &#124; News from Afghanistan & Iraq |newspaper=[[Marine Corps Times]] |access-date=9 July 2012 |archive-url=https://web.archive.org/web/20130602184342/http://www.marinecorpstimes.com/news/2010/08/ap-veterans-affairs-investigation-into-seroquel-083010/ |archive-date=2 June 2013 }}</ref> lawsuits<ref>{{cite web | vauthors= Wilson D |url=https://www.nytimes.com/2011/07/19/health/19drug.html?_r=2 |title=Heart Warning Added to Label on Popular Antipsychotic Drug |publisher=NyTimes |date=19 July 2011 |access-date=9 July 2012 |url-status = live|archive-url=https://web.archive.org/web/20120702172131/http://www.nytimes.com/2011/07/19/health/19drug.html?_r=2 |archive-date=2 July 2012 }}</ref> have been filed against AstraZeneca, alleging that quetiapine caused problems ranging from slurred speech and chronic insomnia to deaths.

===Controversy===
In 2004, a young man named [[Death of Dan Markingson|Dan Markingson]] committed suicide in a controversial Seroquel clinical trial at the University of Minnesota while under an involuntary commitment order.<ref>{{cite news | vauthors = Elliott C |title=The Deadly Corruption of Clinical Trials|url=https://www.motherjones.com/environment/2010/09/dan-markingson-drug-trial-astrazeneca|access-date=2 December 2012|newspaper=Mother Jones|date=September–October 2010|url-status = live|archive-url=https://web.archive.org/web/20121117015108/https://www.motherjones.com/environment/2010/09/dan-markingson-drug-trial-astrazeneca|archive-date=17 November 2012}}</ref> A group of University of Minnesota bioethicists charged that the trial involved an alarming number of ethical violations.<ref>{{cite news| vauthors = Couzin-Frankel J |title=Minnesota bioethicists critique their university|url=http://news.sciencemag.org/scienceinsider/2010/12/minnesota-bioethicists-critique-.html|access-date=2 December 2012|newspaper=Science|date=7 December 2010|archive-url=https://web.archive.org/web/20130221014413/http://news.sciencemag.org/scienceinsider/2010/12/minnesota-bioethicists-critique-.html|archive-date=21 February 2013}}</ref>

===Nurofen Plus tampering case===
In August 2011, the UK's [[Medicines and Healthcare products Regulatory Agency]] (MHRA) issued a class-4 drug alert following reports that some batches of [[Nurofen|Nurofen plus]] contained Seroquel XL tablets instead.<ref>{{cite press release |url=http://www.mhra.gov.uk/NewsCentre/Pressreleases/CON126226 |title=Press release, 25 August 2011 |publisher=MHRA |access-date=9 July 2012 |archive-url=https://web.archive.org/web/20120319232125/http://www.mhra.gov.uk/NewsCentre/Pressreleases/CON126226 |archive-date=19 March 2012 }}</ref>

Following the issue of the Class-4 Drug Alert, Reckitt Benckiser (UK) Ltd received further reports of rogue blister strips in cartons of two additional batches of Nurofen Plus tablets. One of the new batches contained Seroquel XL 50&nbsp;mg tablets and one contained the Pfizer product [[Neurontin]] 100&nbsp;mg capsules.

Following discussions with the MHRA's Defective Medicines Report Centre (DMRC), Reckitt Benckiser (UK) Ltd decided to recall all remaining unexpired stock of Nurofen Plus tablets in any pack size, leading to a Class-1 Drug Alert.<ref>{{cite web |url=http://www.mhra.gov.uk/Publications/Safetywarnings/DrugAlerts/CON126268 |title=Drug Alerts |publisher=MHRA |access-date=9 July 2012 |url-status = live|archive-url=https://web.archive.org/web/20120319232133/http://www.mhra.gov.uk/Publications/Safetywarnings/DrugAlerts/CON126268 |archive-date=19 March 2012 }}</ref> The contamination was later traced to in-store tampering by a customer.<ref>{{cite web |url=https://www.bbc.co.uk/news/uk-england-london-18203634 |title=Nurofen Plus tampering: Christopher McGuire jailed |publisher=[[BBC News]] |date=28 May 2012 |access-date=9 July 2012 |url-status = live|archive-url=https://web.archive.org/web/20120614124729/http://www.bbc.co.uk/news/uk-england-london-18203634 |archive-date=14 June 2012 }}</ref>

== References ==
{{Reflist}}

== External links ==
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