Citalopram

{{Short description|SSRI antidepressant}} {{About|the racemic form of the drug|its (''S'')-enantiomer|Escitalopram}} {{cs1 config|name-list-style=vanc|display-authors=6}} {{Use dmy dates|date=September 2024}}

{{Drugbox | Watchedfields = changed | verifiedrevid = 443526669 | image = Citalopram racemic.svg | image_class = skin-invert-image | width = 190 | caption = (''R'')-(−)-citalopram (top), (''S'')-(+)-citalopram (bottom) | chirality = Racemic mixture

| pronounce = {{IPAc-en|s|aɪ|ˈ|t|æ|l|ə|ˌ|p|r|æ|m|,_|s|ɪ|-}};{{refn|{{MerriamWebsterDictionary|Citalopram}}}} {{respell|sy|TA|lə|pram}} | tradename = Celexa, Cipramil, others<ref name="Citalopram International" /> | Drugs.com = {{drugs.com|monograph|citalopram-hydrobromide}} | MedlinePlus = a699001 | DailyMedID = Citalopram | pregnancy_AU = C | pregnancy_AU_comment = <ref name="Drugs.com pregnancy">{{cite web | title = Citalopram (Celexa) Use During Pregnancy | url = https://www.drugs.com/pregnancy/citalopram.html | website = Drugs.com | access-date = 23 December 2018 | archive-date = 23 December 2018 | archive-url = https://web.archive.org/web/20181223073744/https://www.drugs.com/pregnancy/citalopram.html | url-status = live }}</ref> | dependency_liability = Low | routes_of_administration = oral, intravenous<ref name="Kasper_2002">{{cite journal | vauthors = Kasper S, Müller-Spahn F | title = Intravenous antidepressant treatment: focus on citalopram | journal = European Archives of Psychiatry and Clinical Neuroscience | volume = 252 | issue = 3 | pages = 105–109 | date = June 2002 | pmid = 12192466 | doi = 10.1007/s00406-002-0363-8 | s2cid = 24991131 }}</ref><ref name="Pallanti_2002" /><ref name="citalopramvsclomipramine" /> | class = Selective serotonin reuptake inhibitor (SSRI)<ref name="AHFS2018" /> | ATC_prefix = N06 | ATC_suffix = AB04 | ATC_supplemental = | legal_AU = S4 | legal_BR = C1 | legal_BR_comment = <ref>{{cite web | vauthors = Anvisa | title = RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial | date = 31 March 2023 | 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="Celexa FDA label" />

| bioavailability = 80% peak at 4 hours<ref name="AHFS2018" /> | protein_bound = <80%<ref name="Celexa FDA label">{{cite web | title = Celexa- citalopram tablet, film coated | date = 15 August 2019 | website = DailyMed | url = https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4259d9b1-de34-43a4-85a8-41dd214e9177 | access-date = 28 October 2020 | archive-date = 12 October 2023 | archive-url = https://web.archive.org/web/20231012122423/https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4259d9b1-de34-43a4-85a8-41dd214e9177 | url-status = live }}</ref> | metabolism = Liver (CYP3A4 and CYP2C19) | metabolites = Desmethylcitalopram (DCT) and didesmethylcitalopram (DDCT) | elimination_half-life = 35 hours | excretion = Mostly as unmetabolized citalopram, partly DCT, and traces of DDCT in urine

| index2_label = as salt | receptors =  | CAS_number_Ref = {{cascite|correct|??}} | CAS_number = 59729-33-8 | PubChem = 2771 | IUPHAR_ligand = 7547 | DrugBank_Ref = {{drugbankcite|correct|drugbank}} | DrugBank = DB00215 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 2669 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 0DHU5B8D6V | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = D07704 | KEGG2_Ref = {{keggcite|correct|kegg}} | KEGG2 = D00822 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 3723 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 549

| IUPAC_name = (''RS'')-1-[3-(Dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile | C = 20 | H = 21 | F = 1 | N = 2 | O = 1 | SMILES = Fc1ccc(cc1)C3(OCc2cc(C#N)ccc23)CCCN(C)C | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C20H21FN2O/c1-23(2)11-3-10-20(17-5-7-18(21)8-6-17)19-9-4-15(13-22)12-16(19)14-24-20/h4-9,12H,3,10-11,14H2,1-2H3 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = WSEQXVZVJXJVFP-UHFFFAOYSA-N }}

'''Citalopram''', sold under the brand name '''Celexa''' among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class.<ref name="AHFS2018" /><ref name="Celexa FDA label" /> It is used to treat major depressive disorder, obsessive compulsive disorder, panic disorder, and social phobia.<ref name=AHFS2018>{{cite web | title = Citalopram Hydrobromide Monograph for Professionals | url = https://www.drugs.com/monograph/citalopram-hydrobromide.html | website = Drugs.com | publisher = AHFS | access-date = 23 December 2018 | archive-date = 23 December 2018 | archive-url = https://web.archive.org/web/20181223073739/https://www.drugs.com/monograph/citalopram-hydrobromide.html | url-status = live }}</ref> The antidepressant effects may take one to four weeks to occur.<ref name="AHFS2018" /> It is typically taken orally (swallowed by mouth).<ref name="AHFS2018" /><ref name="Celexa FDA label" /> In some European countries, it is sometimes given intravenously (injected into a vein) to initiate treatment, before switching to the oral route of administration for continuation of treatment.<ref name="Kasper_2002" /> It has also been used intravenously in other parts of the world in some other circumstances.<ref name="Pallanti_2002" /><ref name=citalopramvsclomipramine>{{cite journal | vauthors = Altamura AC, Dell'Osso B, Buoli M, Zanoni S, Mundo E | title = Intravenous augmentative citalopram versus clomipramine in partial/nonresponder depressed patients: a short-term, low dose, randomized, placebo-controlled study | journal = Journal of Clinical Psychopharmacology | volume = 28 | issue = 4 | pages = 406–410 | date = August 2008 | pmid = 18626267 | doi = 10.1097/JCP.0b013e31817d5931 | s2cid = 25013120 }}</ref>

Common side effects include nausea, trouble sleeping, sexual problems, shakiness, feeling tired, and sweating.<ref name="AHFS2018" /> In some patients, sexual dysfunction may persist even after the drug is discontinued, a condition known as post-SSRI sexual dysfunction; regulatory agencies including the European Medicines Agency and Health Canada have recommended that citalopram's product labeling warn of this risk.<ref name="Healy2022" /><ref name="PRAC2019" /> Serious side effects include an increased risk of suicide in those under the age of 25, serotonin syndrome, glaucoma, and QT prolongation.<ref name="AHFS2018" />

Citalopram was approved for medical use in the United States in 1998.<ref name="AHFS2018" /> It is on the World Health Organization's List of Essential Medicines.<ref name="WHO23rd">{{cite book | title = The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023) | location = Geneva | year = 2023 | hdl = 10665/371090 | publisher = World Health Organization | id = WHO/MHP/HPS/EML/2023.02 | hdl-access = free }}</ref> It is available as a generic medication.<ref name="BNF76">{{cite book | title = British national formulary: BNF 76 | page = 361 | date = 2018 | publisher = Pharmaceutical Press | isbn = 978-0-85711-338-2 | edition = 76 }}</ref> In 2023, it was the 43rd most commonly prescribed medication in the United States, with more than 14{{nbsp}}million prescriptions.<ref name="Top300Drugs">{{cite web | title = Top 300 of 2023 | url = https://clincalc.com/DrugStats/Top300Drugs.aspx | website = ClinCalc | access-date = 12 August 2025 | archive-date = 12 August 2025 | archive-url = https://web.archive.org/web/20250812130026/https://clincalc.com/DrugStats/Top300Drugs.aspx | url-status = live }}</ref><ref>{{cite web | title = Citalopram Drug Usage Statistics, United States, 2014 - 2023 | website = ClinCalc | url = https://clincalc.com/DrugStats/Drugs/Citalopram | access-date = 18 August 2025 | archive-date = 11 April 2020 | archive-url = https://web.archive.org/web/20200411214356/https://clincalc.com/DrugStats/Drugs/Citalopram | url-status = live }}</ref>

==Medical uses== [[File:Citalopram20-40-2.jpg|thumb|Citalopram HBr tablets in 20-mg (coral, marked 508) and 40-mg (white, marked 509), and a United States one-cent coin (size 19.05 mm/0.75 in)]]

===Depression=== In the United States, citalopram is approved to treat major depressive disorder.<ref>{{cite book | vauthors = Sharbaf Shoar N, Fariba KA, Padhy RK | chapter = Citalopram | title = StatPearls | date = 2020 | pmid = 29489221 | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK482222/ | place = Treasure Island (FL) | publisher = StatPearls Publishing | access-date = 23 October 2020 | archive-date = 20 October 2020 | archive-url = https://web.archive.org/web/20201020102248/https://www.ncbi.nlm.nih.gov/books/NBK482222/ | url-status = live }}</ref> Citalopram appears to have comparable efficacy and superior tolerability relative to other antidepressants.<ref name="Cipriani_2018">{{cite journal | vauthors = Cipriani A, Furukawa TA, Salanti G, Chaimani A, Atkinson LZ, Ogawa Y, Leucht S, Ruhe HG, Turner EH, Higgins JP, Egger M, Takeshima N, Hayasaka Y, Imai H, Shinohara K, Tajika A, Ioannidis JP, Geddes JR | title = Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis | journal = Lancet | volume = 391 | issue = 10128 | pages = 1357–1366 | date = April 2018 | pmid = 29477251 | pmc = 5889788 | doi = 10.1016/S0140-6736(17)32802-7 }}</ref><ref>{{cite journal | vauthors = Khoo AL, Zhou HJ, Teng M, Lin L, Zhao YJ, Soh LB, Mok YM, Lim BP, Gwee KP | title = Network Meta-Analysis and Cost-Effectiveness Analysis of New Generation Antidepressants | journal = CNS Drugs | volume = 29 | issue = 8 | pages = 695–712 | date = August 2015 | pmid = 26293743 | doi = 10.1007/s40263-015-0267-6 | s2cid = 207486435 }}</ref> In the National Institute for Health and Clinical Excellence ranking of ten antidepressants for efficacy and cost-effectiveness, citalopram is fifth in effectiveness (after mirtazapine, escitalopram, venlafaxine, and sertraline) and fourth in cost-effectiveness.<ref>See p410 of {{cite web | title = National Clinical Practice Guideline 90. Depression: The treatment and management of depression in adults, updated edition (2010). | url = https://www.nice.org.uk/guidance/cg90/evidence/full-guidance-243833293 | archive-url = https://web.archive.org/web/20171215084607/https://www.nice.org.uk/guidance/cg90/evidence/full-guidance-243833293 | archive-date = 15 December 2017 | access-date = 27 November 2016 | publisher = National Institute for Health and Clinical Excellence (UK) }}</ref>

Evidence for the effectiveness of citalopram for treating depression in children is uncertain.<ref>{{cite journal | vauthors = Cohen D | title = Should the use of selective serotonin reuptake inhibitors in child and adolescent depression be banned? | journal = Psychotherapy and Psychosomatics | volume = 76 | issue = 1 | pages = 5–14 | date = 2007 | pmid = 17170559 | doi = 10.1159/000096360 | s2cid = 1112192 }}</ref><ref>{{cite journal | vauthors = Carandang C, Jabbal R, Macbride A, Elbe D | title = A review of escitalopram and citalopram in child and adolescent depression | journal = Journal of the Canadian Academy of Child and Adolescent Psychiatry | volume = 20 | issue = 4 | pages = 315–324 | date = November 2011 | pmid = 22114615 | pmc = 3222577 }}</ref>

=== Panic disorder === Citalopram is licensed in the UK<ref>{{cite web | title = Citalopram 20mg Tablets - Summary of Product Characteristics (SmPC) - (emc) | url = https://www.medicines.org.uk/emc/product/5160/smpc | access-date = 15 January 2023 | website = www.medicines.org.uk | archive-date = 7 April 2023 | archive-url = https://web.archive.org/web/20230407204223/https://www.medicines.org.uk/emc/product/5160/smpc }}</ref> and other European countries<ref>Urząd Rejestracji Produktów Leczniczych, Wyrobów Medycznych i Produktów Biobójczych (Office for Registration of Medicinal Products, Medical Devices and Biocides) {{cite web | title = Charakterystyka Produktu Leczniczego | url = http://www.urpl.gov.pl/system/drugs/dcp/charakterystyka/2012-07-02_2012-04-20-spc-citalopramvb-pl.pdf | trans-title = Characteristic Product Leczniczego | language = Polish | work = The Office for Registration of Medicinal Products, Medical Devices and Biocidal Products | access-date = 24 September 2013 | archive-url = https://web.archive.org/web/20131105190501/http://www.urpl.gov.pl/system/drugs/dcp/charakterystyka/2012-07-02_2012-04-20-spc-citalopramvb-pl.pdf | archive-date = 5 November 2013 }}</ref> for panic disorder, with or without agoraphobia.

=== Other === Citalopram may be used off-label to treat anxiety, and dysthymia,<ref>{{cite journal | vauthors = Hellerstein DJ, Batchelder S, Miozzo R, Kreditor D, Hyler S, Gangure D, Clark J | title = Citalopram in the treatment of dysthymic disorder | journal = International Clinical Psychopharmacology | volume = 19 | issue = 3 | pages = 143–148 | date = May 2004 | pmid = 15107656 | doi = 10.1097/00004850-200405000-00004 | s2cid = 24416470 }}</ref> premenstrual dysphoric disorder, body dysmorphic disorder, and obsessive–compulsive disorder.<ref>{{cite journal | vauthors = Pittenger C, Bloch MH | title = Pharmacological treatment of obsessive-compulsive disorder | journal = The Psychiatric Clinics of North America | volume = 37 | issue = 3 | pages = 375–391 | date = September 2014 | pmid = 25150568 | pmc = 4143776 | doi = 10.1016/j.psc.2014.05.006 }}</ref>

It appears to be as effective as fluvoxamine and paroxetine in obsessive–compulsive disorder.<ref>{{cite journal | vauthors = Stein DJ, Montgomery SA, Kasper S, Tanghoj P | title = Predictors of response to pharmacotherapy with citalopram in obsessive-compulsive disorder | journal = International Clinical Psychopharmacology | volume = 16 | issue = 6 | pages = 357–361 | date = November 2001 | pmid = 11712625 | doi = 10.1097/00004850-200111000-00007 | s2cid = 38416051 }}</ref> Some data suggest the effectiveness of intravenous infusion of citalopram in resistant OCD.<ref name="Pallanti_2002">{{cite journal | vauthors = Pallanti S, Quercioli L, Koran LM | title = Citalopram intravenous infusion in resistant obsessive-compulsive disorder: an open trial | journal = The Journal of Clinical Psychiatry | volume = 63 | issue = 9 | pages = 796–801 | date = September 2002 | pmid = 12363120 | doi = 10.4088/JCP.v63n0908 }}</ref> Citalopram is well tolerated and as effective as moclobemide in social anxiety disorder.<ref>{{cite journal | vauthors = Atmaca M, Kuloglu M, Tezcan E, Unal A | title = Efficacy of citalopram and moclobemide in patients with social phobia: some preliminary findings | journal = Human Psychopharmacology | volume = 17 | issue = 8 | pages = 401–405 | date = December 2002 | pmid = 12457375 | doi = 10.1002/hup.436 | s2cid = 34395742 }}</ref> There are studies suggesting that citalopram can be useful in reducing aggressive and impulsive behavior.<ref>{{cite journal | vauthors = Armenteros JL, Lewis JE | title = Citalopram treatment for impulsive aggression in children and adolescents: an open pilot study | journal = Journal of the American Academy of Child and Adolescent Psychiatry | volume = 41 | issue = 5 | pages = 522–529 | date = May 2002 | pmid = 12014784 | doi = 10.1097/00004583-200205000-00009 }}</ref><ref>{{cite journal | vauthors = Reist C, Nakamura K, Sagart E, Sokolski KN, Fujimoto KA | title = Impulsive aggressive behavior: open-label treatment with citalopram | journal = The Journal of Clinical Psychiatry | volume = 64 | issue = 1 | pages = 81–85 | date = January 2003 | pmid = 12590628 | doi = 10.4088/jcp.v64n0115 }}</ref> It appears to be superior to placebo for behavioural disturbances associated with dementia.<ref>{{cite journal | vauthors = Pollock BG, Mulsant BH, Rosen J, Sweet RA, Mazumdar S, Bharucha A, Marin R, Jacob NJ, Huber KA, Kastango KB, Chew ML | title = Comparison of citalopram, perphenazine, and placebo for the acute treatment of psychosis and behavioral disturbances in hospitalized, demented patients | journal = The American Journal of Psychiatry | volume = 159 | issue = 3 | pages = 460–465 | date = March 2002 | pmid = 11870012 | doi = 10.1176/appi.ajp.159.3.460 }}</ref> It has also been used successfully for hypersexuality in early Alzheimer's disease.<ref>{{cite journal | vauthors = Tosto G, Talarico G, Lenzi GL, Bruno G | title = Effect of citalopram in treating hypersexuality in an Alzheimer's disease case | journal = Neurological Sciences | volume = 29 | issue = 4 | pages = 269–270 | date = September 2008 | pmid = 18810603 | doi = 10.1007/s10072-008-0979-1 | s2cid = 11432563 | hdl = 11573/22581 }}</ref>

A meta-analysis, including studies with fluoxetine, paroxetine, sertraline, escitalopram, and citalopram versus placebo, showed SSRIs to be effective in reducing symptoms of premenstrual syndrome, whether taken continuously or just in the luteal phase.<ref>{{cite journal | vauthors = Jespersen C, Lauritsen MP, Frokjaer VG, Schroll JB | title = Selective serotonin reuptake inhibitors for premenstrual syndrome and premenstrual dysphoric disorder | journal = The Cochrane Database of Systematic Reviews | volume = 2024 | issue = 8 | article-number = CD001396 | date = August 2024 | pmid = 39140320 | pmc = 11323276 | doi = 10.1002/14651858.CD001396.pub4 }}</ref> For alcoholism, citalopram has produced a modest reduction alcohol intake and increase in drink-free days in studies of alcoholics, possibly by decreasing desire or reducing the reward.<ref>{{cite journal | vauthors = Tiihonen J, Ryynänen OP, Kauhanen J, Hakola HP, Salaspuro M | title = Citalopram in the treatment of alcoholism: a double-blind placebo-controlled study | journal = Pharmacopsychiatry | volume = 29 | issue = 1 | pages = 27–29 | date = January 1996 | pmid = 8852531 | doi = 10.1055/s-2007-979538 | s2cid = 260242756 }}</ref>

While on its own citalopram is less effective than amitriptyline in the prevention of migraines, in refractory cases, combination therapy may be more effective.<ref name="Rampello_2004">{{cite journal | vauthors = Rampello L, Alvano A, Chiechio S, Malaguarnera M, Raffaele R, Vecchio I, Nicoletti F | title = Evaluation of the prophylactic efficacy of amitriptyline and citalopram, alone or in combination, in patients with comorbidity of depression, migraine, and tension-type headache | journal = Neuropsychobiology | volume = 50 | issue = 4 | pages = 322–328 | year = 2004 | pmid = 15539864 | doi = 10.1159/000080960 | s2cid = 46362166 }}</ref>

Citalopram and other SSRIs can be used to treat hot flashes.<ref name="Stahl_2011">{{cite book | vauthors = Stahl SM | title = The Prescriber's Guide (Stahl's Essential Psychopharmacology) | location = Cambridge, UK | year = 2011 | publisher = Cambridge University Press | isbn = 978-0-521-17364-3 }}</ref>{{rp|107}}

A 2009 multisite randomized controlled study found no benefit and some adverse effects in autistic children from citalopram, raising doubts about whether SSRIs are effective for treating repetitive behavior in children with autism.<ref name="King_2009">{{cite journal | vauthors = King BH, Hollander E, Sikich L, McCracken JT, Scahill L, Bregman JD, Donnelly CL, Anagnostou E, Dukes K, Sullivan L, Hirtz D, Wagner A, Ritz L | title = Lack of efficacy of citalopram in children with autism spectrum disorders and high levels of repetitive behavior: citalopram ineffective in children with autism | journal = Archives of General Psychiatry | volume = 66 | issue = 6 | pages = 583–590 | date = June 2009 | pmid = 19487623 | pmc = 4112556 | doi = 10.1001/archgenpsychiatry.2009.30 }} *{{lay source |template = cite news|vauthors = Kaplan K|url = http://www.latimes.com/news/science/la-sci-autism-drugs2-2009jun02,0,6717060.story|title = Study finds antidepressant doesn't help autistic children |date= 2 June 2009 |website = Los Angeles Times }}</ref>

Some research suggests citalopram interacts with cannabinoid protein-couplings in the rat brain, and this is put forward as a potential cause of some of the drug's antidepressant effects.<ref name="Hesketh_2008">{{cite journal | vauthors = Hesketh SA, Brennan AK, Jessop DS, Finn DP | title = Effects of chronic treatment with citalopram on cannabinoid and opioid receptor-mediated G-protein coupling in discrete rat brain regions | journal = Psychopharmacology | volume = 198 | issue = 1 | pages = 29–36 | date = May 2008 | pmid = 18084745 | doi = 10.1007/s00213-007-1033-3 | s2cid = 23357324 }}</ref>

== Administration == Citalopram is typically taken in one dose, either in the morning or evening. It can be taken with or without food. Its absorption does not increase when taken with food,<ref name="Citalopram_PI_Sheet">{{cite web | title = Celexa (citalopram hydrobromide) Tablets/Oral Solution | url = http://www.frx.com/pi/celexa_pi.pdf | work = Prescribing Information | publisher = Forest Laboratories, Inc. | access-date = 20 October 2012 | archive-date = 21 October 2014 | archive-url = https://web.archive.org/web/20141021034713/http://www.frx.com/pi/celexa_pi.pdf | url-status = live }}</ref><ref name="Celexa FDA label" /> but doing so can help prevent nausea. Nausea is often caused when the 5-HT3 receptors actively absorb free serotonin, as this receptor is present within the digestive tract.<ref name="Rang_2003">{{cite book | vauthors = Rang HP | title = Pharmacology | location = Edinburgh | year = 2003 | publisher = Churchill Livingstone | isbn = 978-0-443-07145-4 | page = 187 }}</ref>

==Adverse effects== Citalopram theoretically causes side effects by increasing the concentration of serotonin in other parts of the body (e.g., the intestines). Other side effects, such as increased apathy and emotional flattening, may be caused by the decrease in dopamine release associated with increased serotonin. Citalopram is also a mild antihistamine, which may be responsible for some of its sedating properties.<ref name="Stahl_2011" />{{rp|104}}

Other common side effects of citalopram include drowsiness, insomnia, nausea, weight changes (usually weight gain), increase in appetite, vivid dreaming, frequent urination, dry mouth,<ref name="Citalopram_PI_Sheet" /> increased sweating, trembling, diarrhea, excessive yawning, severe tinnitus, and fatigue. Less common side effects include bruxism, vomiting, cardiac arrhythmia, blood pressure changes, dilated pupils, anxiety, mood swings, headache, hyperactivity and dizziness. Rare side effects include convulsions, hallucinations, severe allergic reactions and photosensitivity.<ref name="Citalopram_PI_Sheet" /> If sedation occurs, the dose may be taken at bedtime rather than in the morning. Some data suggest citalopram may cause nightmares.<ref>{{cite journal | vauthors = Arora G, Sandhu G, Fleser C | title = Citalopram and nightmares | journal = The Journal of Neuropsychiatry and Clinical Neurosciences | volume = 24 | issue = 2 | pages = E43 | date = Spring 2012 | pmid = 22772700 | doi = 10.1176/appi.neuropsych.11040096 }}</ref> Citalopram is associated with a higher risk of arrhythmia than other SSRIs.<ref>{{cite journal | vauthors = Qirjazi E, McArthur E, Nash DM, Dixon SN, Weir MA, Vasudev A, Jandoc R, Gula LJ, Oliver MJ, Wald R, Garg AX | title = Risk of Ventricular Arrhythmia with Citalopram and Escitalopram: A Population-Based Study | journal = PLOS ONE | volume = 11 | issue = 8 | article-number = e0160768 | date = 11 August 2016 | pmid = 27513855 | pmc = 4981428 | doi = 10.1371/journal.pone.0160768 | bibcode = 2016PLoSO..1160768Q | doi-access = free }}</ref><ref>{{cite journal | vauthors = Girardin FR, Gex-Fabry M, Berney P, Shah D, Gaspoz JM, Dayer P | title = Drug-induced long QT in adult psychiatric inpatients: the 5-year cross-sectional ECG Screening Outcome in Psychiatry study | journal = The American Journal of Psychiatry | volume = 170 | issue = 12 | pages = 1468–1476 | date = December 2013 | pmid = 24306340 | doi = 10.1176/appi.ajp.2013.12060860 }}</ref>

Citalopram and other SSRIs can induce a mixed state, especially in those with undiagnosed bipolar disorder.<ref name="Stahl_2011" />{{rp|105}} {{cs1 config|name-list-style=vanc|display-authors=6}} One of the other rare side effects of citalopram is visual snow syndrome which does not resolve after the discontinuation of the medicine.<ref>{{cite journal | vauthors = Eren OE, Schöberl F, Schankin CJ, Straube A | date = February 2021 | title = Visual snow syndrome after start of citalopram-novel insights into underlying pathophysiology | journal = European Journal of Clinical Pharmacology | volume = 77 | issue = 2 | pages = 271–272 | doi = 10.1007/s00228-020-02996-9 | pmc = 7803695 | pmid = 32939564 }}</ref>

=== Post-SSRI sexual dysfunction === {{Main|Post-SSRI sexual dysfunction}}

Sexual dysfunction is a common side effect of citalopram and other SSRIs.<ref name="citee653629b">{{cite web | title = Side effects of citalopram | date = 15 February 2022 | url = https://www.nhs.uk/medicines/citalopram/side-effects-of-citalopram/ | access-date = 19 December 2022 | website = nhs.uk | language = en | archive-date = 19 December 2022 | archive-url = https://web.archive.org/web/20221219221838/https://www.nhs.uk/medicines/citalopram/side-effects-of-citalopram/ | url-status = live }}</ref> In some patients, these effects persist after discontinuation of the drug, a condition known as post-SSRI sexual dysfunction (PSSD).<ref name="Bala2018">{{cite journal | vauthors = Bala A, Tue Nguyen HM, Hellstrom WJ | title = Post-SSRI Sexual Dysfunction: A Literature Review | journal = Sexual Medicine Reviews | volume = 6 | issue = 1 | pages = 29–34 | date = January 2018 | pmid = 28778697 | doi = 10.1016/j.sxmr.2017.07.002 }}</ref><ref name="Healy2022">{{cite journal | vauthors = Healy D, Bahrick A, Bak M, Barbato A, Calabro RS, Chubak BM | title = Diagnostic criteria for enduring sexual dysfunction after treatment with antidepressants, finasteride and isotretinoin | journal = International Journal of Risk & Safety in Medicine | volume = 33 | issue = 1 | pages = 65–76 | date = 2022 | pmid = 34719438 | pmc = 8925105 | doi = 10.3233/JRS-210023 }}</ref> Characteristic symptoms include genital numbness, pleasureless or weak orgasm, loss of libido, and erectile dysfunction; non-sexual symptoms such as emotional blunting and cognitive impairment may also occur.<ref name="Healy2022" /> The condition can arise after even brief exposure to a serotonin reuptake inhibitor and may persist indefinitely; there is currently no established treatment.<ref name="Healy2018">{{cite journal | vauthors = Healy D, Le Noury J, Mangin D | title = Enduring sexual dysfunction after treatment with antidepressants, 5-alpha-reductase inhibitors and isotretinoin: 300 cases | journal = International Journal of Risk & Safety in Medicine | volume = 29 | issue = 3–4 | pages = 125–134 | date = 2018 | pmid = 29733030 | doi = 10.3233/JRS-180744 }}</ref> The DSM-5 noted in 2013 that serotonin reuptake inhibitor-induced sexual dysfunction may persist after the agent is discontinued.<ref name="American_2013">{{cite book | title = Diagnostic and Statistical Manual of Mental Disorders | location = Arlington, VA | pages = [https://archive.org/details/diagnosticstatis0005unse/page/449 446–449] | year = 2013 | publisher = American Psychiatric Publishing | isbn = 978-0-89042-555-8 | edition = 5th }}</ref><ref name="Healy2024barriers">{{cite journal | vauthors = Healy D, Mangin D | title = Post-SSRI sexual dysfunction: barriers to quantifying incidence and prevalence | journal = Epidemiology and Psychiatric Sciences | volume = 33 | article-number = e52 | date = 2024 | pmid = 39363727 | pmc = 11450419 | doi = 10.1017/S2045796024000532 | doi-access = free }}</ref>

A 2023 retrospective cohort study of over 12,000 males estimated the risk of irreversible sexual dysfunction at approximately 0.46% of patients treated with serotonergic antidepressants, including SSRIs, though the actual prevalence remains uncertain and the condition is likely underreported.<ref name="BenSheetrit2023">{{cite journal | vauthors = Ben-Sheetrit J, Aizenberg D, Csoka AB, Weizman A, Hermesh H | title = Estimating the risk of irreversible post-SSRI sexual dysfunction (PSSD) due to serotonergic antidepressants | journal = Annals of General Psychiatry | volume = 22 | issue = 1 | article-number = 15 | date = April 2023 | pmid = 37076856 | pmc = 10122283 | doi = 10.1186/s12991-023-00447-0 | doi-access = free }}</ref> A 2023 systematic review found that citalopram was the second most frequently reported SSRI in PSSD case reports, after escitalopram.<ref name="Tarchi2023">{{cite journal | vauthors = Tarchi L, Merola GP, Ferrara M, Ferraro E, Ferrando L, Castellini G, Ricca V | title = Selective serotonin reuptake inhibitors, post-treatment sexual dysfunction and persistent genital arousal disorder: A systematic review | journal = Pharmacoepidemiology and Drug Safety | volume = 32 | issue = 10 | pages = 1041–1055 | date = October 2023 | pmid = 37345683 | doi = 10.1002/pds.5653 }}</ref>

In 2019, the European Medicines Agency's Pharmacovigilance Risk Assessment Committee (PRAC) recommended that product labels for all SSRIs and SNRIs, including citalopram, be updated to state that sexual dysfunction may be long-lasting even after treatment is stopped.<ref name="PRAC2019">{{cite web | title = PRAC recommendations on signals adopted at the 13-16 May 2019 PRAC meeting | publisher = European Medicines Agency | date = 11 June 2019 | url = https://www.ema.europa.eu/en/documents/prac-recommendation/prac-recommendations-signals-adopted-13-16-may-2019-prac-meeting_en.pdf | access-date = 8 April 2026 }}</ref> Health Canada followed with similar label updates in 2021.<ref name="Healy2024barriers" /> In 2024, Australia's Therapeutic Goods Administration aligned all SSRI and SNRI product information to reflect this risk; citalopram was among the products requiring updated warnings.<ref name="TGA2024">{{cite web | title = Updated warnings about persistent sexual dysfunction for antidepressants | publisher = Therapeutic Goods Administration | date = 23 May 2024 | url = https://www.tga.gov.au/news/safety-updates/updated-warnings-about-persistent-sexual-dysfunction-antidepressants | access-date = 8 April 2026 }}</ref>

=== Abnormal heart rhythm === In August 2011, the FDA announced, "Citalopram causes dose-dependent QT interval prolongation. Citalopram should no longer be prescribed at doses greater than 40 mg per day".<ref name="FDA Drug Safety Communication Celexa">{{cite web | title = Abnormal heart rhythms associated with high doses of Celexa (citalopram hydrobromide) | date = 24 August 2011 | url = https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-abnormal-heart-rhythms-associated-high-doses-celexa-citalopram | archive-url = https://web.archive.org/web/20191008021344/https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-abnormal-heart-rhythms-associated-high-doses-celexa-citalopram | archive-date = 8 October 2019 | work = Safety Communication | publisher = U.S. Food and Drug Administration (FDA) }}</ref> A further clarification, issued in March 2012, restricted the maximum dose to 20 mg for subgroups of patients, including those older than 60 years and those taking an inhibitor of cytochrome P450 2C19.7.<ref>{{cite web | title = Revised recommendations for Celexa | date = 28 March 2012 | website = U.S. Food and Drug Administration (FDA) | url = https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-revised-recommendations-celexa-citalopram-hydrobromide-related | archive-url = https://web.archive.org/web/20191213203345/https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-revised-recommendations-celexa-citalopram-hydrobromide-related | archive-date = 13 December 2019 | access-date = 28 October 2020 }}</ref>

=== Endocrine effects === As with other SSRIs, citalopram can cause an increase in serum prolactin level.<ref>{{cite journal | vauthors = Trenque T, Herlem E, Auriche P, Dramé M | title = Serotonin reuptake inhibitors and hyperprolactinaemia: a case/non-case study in the French pharmacovigilance database | journal = Drug Safety | volume = 34 | issue = 12 | pages = 1161–1166 | date = December 2011 | pmid = 22077504 | doi = 10.2165/11595660-000000000-00000 | s2cid = 25532853 }}</ref> Citalopram has no significant effect on insulin sensitivity in women of reproductive age<ref>{{cite journal | vauthors = Kauffman RP, Castracane VD, White DL, Baldock SD, Owens R | title = Impact of the selective serotonin reuptake inhibitor citalopram on insulin sensitivity, leptin and basal cortisol secretion in depressed and non-depressed euglycemic women of reproductive age | journal = Gynecological Endocrinology | volume = 21 | issue = 3 | pages = 129–137 | date = September 2005 | pmid = 16335904 | doi = 10.1080/09513590500216800 | s2cid = 11286706 }}</ref> and no changes in glycaemic control were seen in another trial.<ref name="Sindrup_1992">{{cite journal | vauthors = Sindrup SH, Bjerre U, Dejgaard A, Brøsen K, Aaes-Jørgensen T, Gram LF | title = The selective serotonin reuptake inhibitor citalopram relieves the symptoms of diabetic neuropathy | journal = Clinical Pharmacology and Therapeutics | volume = 52 | issue = 5 | pages = 547–552 | date = November 1992 | pmid = 1424428 | doi = 10.1038/clpt.1992.183 | s2cid = 6730763 }}</ref>

=== Exposure in pregnancy === Antidepressant exposure (including citalopram) during pregnancy is associated with shorter duration of gestation (by three days), increased risk of preterm delivery (by 55%), lower birth weight (by 75 g), and lower Apgar scores (by <0.4 points). Antidepressant exposure is not associated with an increased risk of spontaneous abortion.<ref>{{cite journal | vauthors = Ross LE, Grigoriadis S, Mamisashvili L, Vonderporten EH, Roerecke M, Rehm J, Dennis CL, Koren G, Steiner M, Mousmanis P, Cheung A | title = Selected pregnancy and delivery outcomes after exposure to antidepressant medication: a systematic review and meta-analysis | journal = JAMA Psychiatry | volume = 70 | issue = 4 | pages = 436–443 | date = April 2013 | pmid = 23446732 | doi = 10.1001/jamapsychiatry.2013.684 | doi-access = free }}</ref> It is uncertain whether there is an increased prevalence of septal heart defects among children whose mothers were prescribed an SSRI in early pregnancy.<ref>{{cite journal | vauthors = Pedersen LH, Henriksen TB, Vestergaard M, Olsen J, Bech BH | title = Selective serotonin reuptake inhibitors in pregnancy and congenital malformations: population based cohort study | journal = BMJ | volume = 339 | issue = sep23 1 | article-number = b3569 | date = September 2009 | pmid = 19776103 | pmc = 2749925 | doi = 10.1136/bmj.b3569 }}</ref><ref>{{cite journal | vauthors = Huybrechts KF, Palmsten K, Avorn J, Cohen LS, Holmes LB, Franklin JM, Mogun H, Levin R, Kowal M, Setoguchi S, Hernández-Díaz S | title = Antidepressant use in pregnancy and the risk of cardiac defects | journal = The New England Journal of Medicine | volume = 370 | issue = 25 | pages = 2397–2407 | date = June 2014 | pmid = 24941178 | pmc = 4062924 | doi = 10.1056/NEJMoa1312828 }}</ref>

=== Overdose === Overdosage may result in vomiting, sedation, disturbances in heart rhythm, dizziness, sweating, nausea, tremors, and rarely amnesia, confusion, coma, or convulsions.<ref name="Stahl_2011" />{{rp|105}} Overdose deaths have occurred, sometimes involving other drugs, but also with citalopram as the sole agent. Citalopram and N-desmethylcitalopram may be quantified in blood or plasma to confirm a diagnosis of poisoning in hospitalized patients or to assist in a medicolegal death investigation. Blood or plasma citalopram concentrations are usually in a range of 50-400 μg/L in persons receiving the drug therapeutically, 1000–3000 μg/L in patients who survive acute overdosage, and 3–30 mg/L in those who do not survive.<ref name="FDA Drug Safety Communication Celexa" /><ref name="Personne_1997">{{cite journal | vauthors = Personne M, Sjöberg G, Persson H | title = Citalopram overdose--review of cases treated in Swedish hospitals | journal = Journal of Toxicology. Clinical Toxicology | volume = 35 | issue = 3 | pages = 237–240 | year = 1997 | pmid = 9140316 | doi = 10.3109/15563659709001206 }}</ref><ref name="Luchini_2005">{{cite journal | vauthors = Luchini D, Morabito G, Centini F | title = Case report of a fatal intoxication by citalopram | journal = The American Journal of Forensic Medicine and Pathology | volume = 26 | issue = 4 | pages = 352–354 | date = December 2005 | pmid = 16304470 | doi = 10.1097/01.paf.0000188276.33030.dd | s2cid = 44840526 }}</ref> It is the most dangerous of SSRIs in overdose.<ref name="Taylor_2012">{{cite book | vauthors = Taylor D, Paton C, Kapur S | title = The Maudsley Prescribing Guidelines in Psychiatry (Taylor, The Maudsley Prescribing Guidelines) | location = Hoboken, NJ, USA | year = 2012 | publisher = Wiley-Blackwell | isbn = 978-0-470-97969-3 | page = 588 }}</ref>

===Suicidality=== In the United States, citalopram carries a boxed warning stating it may increase suicidal thinking and behavior in those under age 24.<ref name="Citalopram_PI_Sheet" />

=== Discontinuation syndrome === SSRI discontinuation syndrome has been reported when treatment is stopped. It includes sensory, and gastrointestinal symptoms, dizziness, lethargy, and sleep disturbances, as well as psychological symptoms such as anxiety/agitation, irritability, and poor concentration.<ref>{{cite journal | vauthors = Warner CH, Bobo W, Warner C, Reid S, Rachal J | title = Antidepressant discontinuation syndrome | journal = American Family Physician | volume = 74 | issue = 3 | pages = 449–456 | date = August 2006 | pmid = 16913164 }}</ref> Electric shock-like sensations are typical for SSRI discontinuation.<ref>{{cite journal | vauthors = Prakash O, Dhar V | title = Emergence of electric shock-like sensations on escitalopram discontinuation | journal = Journal of Clinical Psychopharmacology | volume = 28 | issue = 3 | pages = 359–360 | date = June 2008 | pmid = 18480703 | doi = 10.1097/JCP.0b013e3181727534 }}</ref> Withdrawal symptoms can occur when this medicine is suddenly stopped, such as paraesthesiae, sleeping problems (difficulty sleeping and intense dreams), feeling dizzy, agitated or anxious, nausea, vomiting, tremors, confusion, sweating, headache, diarrhea, palpitations, changes in emotions, irritability, and eye or eyesight problems. Treatment with citalopram should be reduced gradually when treatment is finished.<ref>{{cite web | title = Citalopram withdrawal: What to expect | date = 13 October 2022 | url = https://www.medicalnewstoday.com/articles/citalopram-withdrawal | access-date = 19 December 2022 | website = www.medicalnewstoday.com | language = en | archive-date = 19 December 2022 | archive-url = https://web.archive.org/web/20221219223014/https://www.medicalnewstoday.com/articles/citalopram-withdrawal | url-status = live }}</ref>

== Interactions ==

=== Serotonin syndrome === Citalopram should not be taken with St John's wort, tryptophan or 5-HTP as the resulting drug interaction could lead to serotonin syndrome.<ref name="Karch_2006">{{cite book | vauthors = Karch AM | title = Lippincott's Nursing Drug Guide | location = Hagerstwon, MD | year = 2006 | publisher = Lippincott Williams & Wilkins | isbn = 978-1-58255-436-5 }}</ref> With St John's wort, this may be caused by compounds in the plant extract reducing the efficacy of the hepatic cytochrome P450 enzymes that process citalopram.<ref name="urlInteractions with St Johns wort preparations">{{cite web | title = Interactions with St John's wort preparations | year = 2000 | url = http://www.medsafe.govt.nz/Profs/PUarticles/sjw.htm | work = Prescriber Update Articles | publisher = New Zealand Medicines and Medical Devices Safety Authority | access-date = 27 February 2009 | archive-date = 3 February 2009 | archive-url = https://web.archive.org/web/20090203174310/http://medsafe.govt.nz/Profs/PUarticles/sjw.htm | url-status = live }}</ref> Tryptophan and 5-HTP are precursors to serotonin.<ref>{{cite web | title = The History of Tryptophan, Serotonin and 5-HTP | date = 21 November 2016 | url = https://www.oxfordvitality.co.uk/history-5-htp-serotonin-tryptophan | website = www.oxfordvitality.co.uk | language = en | access-date = 22 July 2018 | archive-date = 23 July 2018 | archive-url = https://web.archive.org/web/20180723003532/https://www.oxfordvitality.co.uk/history-5-htp-serotonin-tryptophan | url-status = live }}</ref> When taken with an SSRI, such as citalopram, this can lead to levels of serotonin that can be lethal. This may also be the case when SSRIs are taken with SRAs (serotonin releasing agents) such as in the case of MDMA. It is possible that SSRIs could reduce the effects associated with an SRA since SSRIs stop the reuptake of Serotonin by blocking SERT. This would allow less serotonin in and out of the transporters, thus decreasing the likelihood of neurotoxic effects. However, these concerns are still disputed as the exact pharmacodynamic effects of citalopram and MDMA have yet to be fully identified.{{citation needed|date=September 2015}} Citalopram is contraindicated in individuals taking MAOIs, owing to a potential for serotonin syndrome.

=== Other interactions === SSRIs, including citalopram, can increase the risk of bleeding, especially when coupled with aspirin, NSAIDs, warfarin, or other anticoagulants.<ref name="Citalopram_PI_Sheet" /> Taking citalopram with omeprazole may cause higher blood levels of citalopram. This is a potentially dangerous interaction, so dosage adjustments may be needed or alternatives may be prescribed.<ref>{{cite web | title = Drug interactions between Celexa and omeprazole | url = https://www.drugs.com/drug-interactions/celexa-with-omeprazole-679-335-1750-0.html | publisher = Drugs.com | access-date = 28 January 2014 | archive-date = 1 February 2014 | archive-url = https://web.archive.org/web/20140201175603/http://www.drugs.com/drug-interactions/celexa-with-omeprazole-679-335-1750-0.html | url-status = live }}</ref><ref>{{cite web | title = citalopram (Rx) - Celexa | url = http://reference.medscape.com/drug/celexa-citalopram-342958 | publisher = Medscape | access-date = 28 January 2014 | archive-date = 5 December 2013 | archive-url = https://web.archive.org/web/20131205120008/http://reference.medscape.com/drug/celexa-citalopram-342958 | url-status = live }}</ref><ref name="Celexa FDA label" />

== Pharmacology ==

=== Pharmacodynamics === Citalopram contains two pharmacodynamically distinct enantiomers: (S)-citalopram (escitalopram) and (R)-citalopram. (S)-citalopram is a highly selective serotonin reuptake inhibitor and is thought to be responsible for most of the SRI activity of citalopram.<ref>{{cite journal | vauthors = El Mansari M, Sánchez C, Chouvet G, Renaud B, Haddjeri N | title = Effects of acute and long-term administration of escitalopram and citalopram on serotonin neurotransmission: an in vivo electrophysiological study in rat brain | journal = Neuropsychopharmacology | volume = 30 | issue = 7 | pages = 1269–1277 | date = July 2005 | pmid = 15702136 | doi = 10.1038/sj.npp.1300686 }}</ref><ref>{{cite journal | vauthors = Sánchez C, Bøgesø KP, Ebert B, Reines EH, Braestrup C | title = Escitalopram versus citalopram: the surprising role of the R-enantiomer | journal = Psychopharmacology | volume = 174 | issue = 2 | pages = 163–176 | date = July 2004 | pmid = 15160261 | doi = 10.1007/s00213-004-1865-z }}</ref> (R)-citalopram, by comparison, is a 20-fold less potent SERT inhibitor and antagonizes the actions of (S)-citalopram at this site.<ref name="Storustovu_Si_2004">{{cite journal | vauthors = Stórustovu S, Sánchez C, Pörzgen P, Brennum LT, Larsen AK, Pulis M, Ebert B | title = R-citalopram functionally antagonises escitalopram in vivo and in vitro: evidence for kinetic interaction at the serotonin transporter | journal = British Journal of Pharmacology | volume = 142 | issue = 1 | pages = 172–180 | date = May 2004 | pmid = 15037515 | pmc = 1574928 | doi = 10.1038/sj.bjp.0705738 }}</ref><ref>{{cite journal | vauthors = Mørk A, Kreilgaard M, Sánchez C | title = The R-enantiomer of citalopram counteracts escitalopram-induced increase in extracellular 5-HT in the frontal cortex of freely moving rats | journal = Neuropharmacology | volume = 45 | issue = 2 | pages = 167–173 | date = August 2003 | pmid = 12842122 | doi = 10.1016/S0028-3908(03)00138-2 }}</ref> The mechanism of antagonism is uncertain, but may involve kinetic interactions between the two; it has been proposed that the long-lasting inhibited state of SERT induced by (S)-citalopram may be attenuated by (R)-citalopram binding.<ref name="Storustovu_Si_2004" />

Citalopram has a ~6-fold higher affinity for H1 histamine receptors than (S)-citalopram (Ki = 257nM vs 1500nM), though the clinical significance of this difference is unknown.<ref name="Sanchez_2003">{{cite journal | vauthors = Sánchez C, Bergqvist PB, Brennum LT, Gupta S, Hogg S, Larsen A, Wiborg O | title = Escitalopram, the S-(+)-enantiomer of citalopram, is a selective serotonin reuptake inhibitor with potent effects in animal models predictive of antidepressant and anxiolytic activities | journal = Psychopharmacology | volume = 167 | issue = 4 | pages = 353–362 | date = June 2003 | pmid = 12719960 | doi = 10.1007/s00213-002-1364-z }}</ref> Both citalopram and escitalopram have similar affinities for the σ1 receptor (Ki = 50nM).<ref name="Sanchez_2003" />

=== Pharmacokinetics === Citalopram is considered safe and well tolerated in the therapeutic dose range. Distinct from some other agents in its class, it exhibits linear pharmacokinetics and minimal drug interaction potential, making it a better choice for the elderly or comorbid patients.<ref name="Keller_2000">{{cite journal | vauthors = Keller MB | title = Citalopram therapy for depression: a review of 10 years of European experience and data from U.S. clinical trials | journal = The Journal of Clinical Psychiatry | volume = 61 | issue = 12 | pages = 896–908 | date = December 2000 | pmid = 11206593 | doi = 10.4088/JCP.v61n1202 }}</ref>

== Stereochemistry == Citalopram has one stereocenter, to which a 4-fluoro phenyl group and an ''N, N''-dimethyl-3-aminopropyl group bind. As a result of this chirality, the molecule exists in (two) enantiomeric forms (mirror images). They are termed ''S''-(+)-citalopram and ''R''-(–)-citalopram. {| style="margin:auto" |- | align="center" | 200px | align="center" | 200px |- | align="center" | class=skin-invert-image|200px | align="center" | class=skin-invert-image|200px |- | align="center" | '''(''S'')-(+)-citalopram''' | align="center" | '''(''R'')-(–)-citalopram''' |}

Citalopram is sold as a racemic mixture, consisting of 50% (''R'')-(−)-citalopram and 50% (''S'')-(+)-citalopram. Only the (''S'')-(+) enantiomer has the desired antidepressant effect.<ref name="Lepola_2004">{{cite journal | vauthors = Lepola U, Wade A, Andersen HF | title = Do equivalent doses of escitalopram and citalopram have similar efficacy? A pooled analysis of two positive placebo-controlled studies in major depressive disorder | journal = International Clinical Psychopharmacology | volume = 19 | issue = 3 | pages = 149–155 | date = May 2004 | pmid = 15107657 | doi = 10.1097/00004850-200405000-00005 | s2cid = 36768144 }}</ref> Lundbeck now markets the (''S'')-(+) enantiomer, the generic name of which is escitalopram. Whereas citalopram is supplied as the hydrobromide, escitalopram is sold as the oxalate salt (hydrooxalate).<ref name="Citalopram_PI_Sheet" /> In both cases, the salt forms of the amine make these otherwise lipophilic compounds water-soluble.

==Metabolism== Citalopram is metabolized in the liver mostly by CYP2C19, but also by CYP3A4 and CYP2D6. Metabolites desmethylcitalopram and didesmethylcitalopram are significantly less energetic and their contribution to the overall action of citalopram is negligible. The half-life of citalopram is about 35 hours. Approximately 80% is cleared by the liver and 20% by the kidneys.<ref name="DrugBank">{{cite web | title = Citalopram | date = 17 August 2016 | url = https://www.drugbank.ca/drugs/DB00215 | website = DrugBank | access-date = 12 February 2017 | archive-date = 12 February 2017 | archive-url = https://web.archive.org/web/20170212164636/https://www.drugbank.ca/drugs/DB00215 | url-status = live }}</ref> The elimination process is slower in the elderly and in patients with liver or kidney failure. With once-daily dosing, steady plasma concentrations are achieved in about a week. Potent inhibitors of CYP2C19 and 3A4 might decrease citalopram clearance.<ref name="Celexa FDA label" /> Tobacco smoke exposure was found to inhibit the biotransformation of citalopram in animals, suggesting that the elimination rate of citalopram is decreased after tobacco smoke exposure. After intragastric administration, the half-life of the racemic mixture of citalopram was increased by about 287%.<ref>{{cite journal | vauthors = Majcherczyk J, Kulza M, Senczuk-Przybylowska M, Florek E, Jawien W, Piekoszewski W | title = Influence of tobacco smoke on the pharmacokinetics of citalopram and its enantiomers | journal = Journal of Physiology and Pharmacology | volume = 63 | issue = 1 | pages = 95–100 | date = February 2012 | pmid = 22460466 }}</ref>

class=skin-invert-image|700px|thumb|center|Metabolism of citalopram in humans<ref>{{cite journal | vauthors = Sangkuhl K, Klein TE, Altman RB | title = PharmGKB summary: citalopram pharmacokinetics pathway | journal = Pharmacogenetics and Genomics | volume = 21 | issue = 11 | pages = 769–772 | date = November 2011 | pmid = 21546862 | pmc = 3349993 | doi = 10.1097/FPC.0b013e328346063f }}</ref><ref>{{cite journal | vauthors = Hiemke C, Härtter S | title = Pharmacokinetics of selective serotonin reuptake inhibitors | journal = Pharmacology & Therapeutics | volume = 85 | issue = 1 | pages = 11–28 | date = January 2000 | pmid = 10674711 | doi = 10.1016/s0163-7258(99)00048-0 }}</ref><ref>{{cite journal | vauthors = Budău M, Hancu G, Rusu A, Muntean DL | title = Analytical methodologies for the enantiodetermination of citalopram and its metabolites | journal = Chirality | volume = 32 | issue = 1 | pages = 32–41 | date = January 2020 | pmid = 31702071 | doi = 10.1002/chir.23139 | s2cid = 207936622 }}</ref>

{| class="wikitable" style="float:right;width:200px;margin:10px" |+Binding profile<ref>{{cite journal | vauthors = Owens JM, Knight DL, Nemeroff CB | title = [Second generation SSRIS: human monoamine transporter binding profile of escitalopram and R-fluoxetine] | journal = L'Encephale | volume = 28 | issue = 4 | pages = 350–355 | date = Jul–Aug 2002 | pmid = 12232544 }}</ref> |- ! Receptor !! Ki (nM) |- | SERT || 1.6 |- | NET || 6190 |- | 5-HT2C || 617 |- | α1 || 1211 |- | M1 || 1430 |- | H1 || 283 |}

==History== Citalopram was first synthesized in 1972 by chemist Klaus Bøgesø<ref>{{cite book | vauthors = Bøgesø KP, Sánchez C | veditors = Fischer J, Ganellin CR, Rotella DP | chapter = The discovery of citalopram and its refinement to escitalopram. | title = Analogue-Based Drug Discovery | location = Weinheim, Germany | volume = III | pages = 269–94 | date = December 2012 | doi = 10.1002/9783527651085.ch11 | chapter-url = https://www.researchgate.net/publication/256067218 | access-date = 23 October 2020 | isbn = 978-3-527-65108-5 | publisher = Wiley-VCH Verlag GmbH & Co. KGaA }}</ref> and his research group at the pharmaceutical company Lundbeck and was first marketed in 1989 in Denmark. It was first marketed in the US in 1998.<ref>{{cite journal | vauthors = Rawe B, May P | title = Citalopram: A new treatment for depression | journal = Molecule of the Month | date = November 2009 | doi = 10.6084/m9.figshare.5255050 | url = http://www.chm.bris.ac.uk/motm/citalopram/citalopramh.htm | access-date = 16 February 2015 | publisher = University of Bristol | archive-date = 1 March 2017 | archive-url = https://web.archive.org/web/20170301222003/http://www.chm.bris.ac.uk/motm/citalopram/citalopramh.htm | url-status = live }}</ref> The original patent expired in 2003, allowing other companies to legally produce and market generic versions.

==Society and culture== ===Brand names=== Citalopram is sold under these brand names:  {{div col|colwidth=25em}} * Akarin (Denmark, Nycomed) * C Pram S (India) * Celapram (Australia,<ref name="url_Citalopram_PBS">{{Cite web | title = Pharmaceutical Benefits Scheme (PBS) - Citalopram | url = http://www.pbs.gov.au/medicine/item/8220p-8702b-8703c | website = Australian Government Department of Health | publisher = Australian Government | access-date = 10 September 2014 | archive-date = 11 September 2014 | archive-url = https://web.archive.org/web/20140911001757/http://www.pbs.gov.au/medicine/item/8220p-8702b-8703c | url-status = live }}</ref> New Zealand), * Celexa (U.S. and Canada, Forest Laboratories, Inc.) * Celica (Australia)<ref name="url_Citalopram_PBS" /> * Ciazil (Australia,<ref name="url_Citalopram_PBS" /> New Zealand) * Cilate (South Africa) * Cilift (South Africa) * Cipram (Denmark, Turkey, H. Lundbeck A/S) * Cipramil (Australia,<ref name="url_Citalopram_PBS" /> Brazil, Belgium, Chile, Finland, Germany, Netherlands, Iceland, Ireland, Israel, New Zealand, Norway, Russia, South Africa, Sweden, United Kingdom) * Cipraned, Cinapen (Greece) * Ciprapine (Ireland) * Ciprotan (Ireland) * Citabax, Citaxin (Poland) * Cital (Poland) * Citalec (Czech Republic, Slovakia) * Citalex (Iran, Serbia) * Citalo (Australia,<ref name="url_Citalopram_PBS" /> Egypt, Pakistan) * Citalopram (Canada, Denmark, Finland, Germany, Ireland, The Netherlands, New Zealand, Spain, Sweden, Switzerland, United Kingdom, U.S.) * Citol (Russia, Turkey)  * Citox (Mexico) * Citrol (Europe and Australia)<ref name="url_Citalopram_PBS" /> * Citta (Brazil) * Dalsan (Eastern Europe) * Denyl (Brazil) * Depram (Egypt)<ref>{{Cite web | title = Depram | url = https://apexpharmaeg.com/product/depram/ | access-date = 2024-12-23 | website = Apex | language = en-US }}</ref><ref>{{Cite web | vauthors = El-beltagy M | date = 5 July 2024 | script-title = ar:ديپرام: كل ما تريد معرفته عنه | trans-title = Depram: all you need to know about it | url = https://www.tebdaily.com/%d8%af%d9%8a%d8%a8%d8%b1%d8%a7%d9%85-%d9%83%d9%84-%d9%85%d8%a7-%d8%aa%d8%b1%d9%8a%d8%af-%d9%85%d8%b9%d8%b1%d9%81%d8%aa%d9%87-%d8%b9%d9%86%d9%87/ | website = Teb Daily | access-date = 23 December 2024 | archive-date = 19 January 2025 | archive-url = https://web.archive.org/web/20250119160227/https://www.tebdaily.com/%D8%AF%D9%8A%D8%A8%D8%B1%D8%A7%D9%85-%D9%83%D9%84-%D9%85%D8%A7-%D8%AA%D8%B1%D9%8A%D8%AF-%D9%85%D8%B9%D8%B1%D9%81%D8%AA%D9%87-%D8%B9%D9%86%D9%87/ | url-status = live }}</ref> * Elopram (Italy) * Estar (Pakistan) * Humorup (Argentina) * Humorap (Peru, Bolivia) * Lopraxer (Greece)<ref>{{Cite web | title = Lopraxer | url = https://www.drugs.com/international/lopraxer.html | department = International | website = Drugs.com | access-date = 12 April 2020 | archive-date = 12 April 2020 | archive-url = https://web.archive.org/web/20200412101246/https://www.drugs.com/international/lopraxer.html | url-status = live }}</ref> * Oropram (Iceland, Actavis), * Opra (Russia) * Pram (Russia) * Pramcit (Pakistan) * Procimax (Brazil) * Recital (Israel, Thrima Inc. for Unipharm Ltd.) * Sepram (Finland) * Seropram (various European countries, including the Czech Republic) * Szetalo (India) * Talam (Europe and Australia)<ref name="url_Citalopram_PBS" />  * Temperax (Argentina, Chile, Peru) * Vodelax (Turkey) * Zentius (South America, by Roemmers and Recalcine) * Zetalo (India) * Cipratal (Kuwait, GCC) * Zylotex (Portugal)<ref name="Citalopram International">{{Cite web | title = Citalopram | url = https://www.drugs.com/international/citalopram.html | department = International | website = Drugs.com | access-date = 23 January 2018 | archive-date = 16 September 2018 | archive-url = https://web.archive.org/web/20180916021137/https://www.drugs.com/international/citalopram.html | url-status = live }}</ref> {{div col end}}

===European Commission fine===

On 19 June 2013, the European Commission imposed a fine of €93.8 million on the Danish pharmaceutical company Lundbeck, plus a total of €52.2 million on several generic pharmaceutical-producing companies. This was in response to Lundbeck entering an agreement with the companies to delay their sales of generic citalopram after Lundbeck's patent on the drug had expired, thus reducing competition in breach of European antitrust law.<ref>{{cite press release | title = Antitrust: Commission fines Lundbeck and other pharma companies for delaying market entry of generic medicines | date = 19 June 2013 | publisher = European Union | place = Brussels | url = http://europa.eu/rapid/press-release_IP-13-563_en.htm | access-date = 20 June 2013 | archive-date = 22 June 2013 | archive-url = https://web.archive.org/web/20130622082028/http://europa.eu/rapid/press-release_IP-13-563_en.htm | url-status = live }}</ref>

== Other uses == Citalopram is also a parasiticide.<ref name="Ribeiro_2010">{{cite journal | vauthors = Ribeiro P, Geary TG | title = Neuronal signaling in schistosomes: current status and prospects for postgenomics | journal = Canadian Journal of Zoology | volume = 88 | issue = 1 | pages = 1–22 | year = 2010 | doi = 10.1139/z09-126 | publisher = Canadian Science Publishing | issn = 0008-4301 }}</ref> Schistosomula have high mortality when treated with citalopram.<ref name="Ribeiro_2010" />

== See also == * List of antidepressants

== References == {{Reflist}} {{Commons}} {{Antidepressants}} {{Anxiolytics}} {{OCD pharmacotherapies}} {{Drugs for erectile dysfunction and premature ejaculation}} {{Monoamine reuptake inhibitors}} {{Sigma receptor modulators}} {{Portal bar | Medicine}} {{Authority control}}

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