Description

Simple

A medication used to treat depression.

Clinical

A selective serotonin reuptake inhibitor (SSRI) used in the treatment of depression.

Overview

Citalopram belongs to a class of antidepressant agents known as selective _serotonin-reuptake inhibitors_ (SSRIs) and is widely used to treat the symptoms of depression. Its chemical structure is unrelated to that of other SSRIs or of tricyclic, tetracyclic, or other prescribed antidepressants [FDA label]. Citalopram is also known as _Celexa_, and available in tablet and solution forms [FDA label]. This drug was initially approved by the FDA in 1998 [18].

Pharmacology

Indication

For the treatment of depression, as indicated by the FDA label [FDA label]. Off-label indications include but are not limited to: treatment of sexual dysfunction, post-stroke behavioural changes, ethanol abuse, obsessive-compulsive disorder (OCD) in children, and diabetic neuropathy [FDA label], [ Read more

Pharmacodynamic

Citalopram belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). It has been found to relieve or manage symptoms of depression, anxiety, eating disorders and obsessive-compulsive disorder among other mood disorders. The antidepressant, anti-anxiety, and othe... Read more

Mechanism of action


The mechanism of action of citalopram results from its inhibition of CNS neuronal reuptake of serotonin (5-HT) [FDA label]. The molecular target for citalopram is the serotonin transporter (solute carrier family 6 member 4, _SLC6A4_), inhibiting its serotonin reuptake in the synaptic cleft [ Read more

Absorption

Rapidly and well absorbed from the GI tract. Peak plasma concentrations occur within 4 hours of a single orally administered dose. Bioavailability is 80% following oral administration. Food does not affect absorption [FDA label].

Protein binding

Citalopram, dimethylcitalopram, and didemethylcitalopram are 80% bound to plasma proteins [FDA label].

Volume of distribution

12 L/kg [FDA label]Citalopram is highly lipophilic and likely widely distributed throughout the body, including the blood-brain-barrier. However, its metabolite, _demethylcitalopram_ does not penetrate the blood-brain-barrier well [FDA label].

Clearance

The systemic clearance of citalopram is 330 mL/min, with approximately 20% renal clearance [FDA label].

Half life

About 35 hours [FDA label].

Route of elimination

12-23% of an oral dose of citalopram is found unchanged in the urine, while 10% of the dose is found in the faeces [FDA label].

Toxicity

**Oral (Human) LD**: 56 mg/kg
**Intraperitoneal (Mouse) LD50**: 179 mg/kg

**Acute toxicity**

Symptoms of toxicity include dizziness, sweating, nausea, vomiting, tremor, somnolence, and sinus tachycardia. Rarely, symptoms included amnesia, confusion, coma, convulsions, hyperventilation, cyanos... Read more

Adverse Effects

Contraindications

  • Regions: US
  • Patient Conditions:
      • Name: Patients with a hypersensitivity to citalopram or any of the inactive ingredients in the formulation of citalopram
      • Drugbank Id: DBCOND0117356
  • Regions: US
  • With Drugs:
      • Name: Pimozide
      • Drugbank Id: DB01100
  • Regions: US
  • With Categories:
      • Name: Monoamine Oxidase Inhibitors
      • Drugbank Id: DBCAT001004
      • Mesh Id: D008996

Food Interactions

  • Avoid alcohol.
  • Avoid St. John's Wort.
  • Take with or without food. The absorption is unaffected by food.

Interactions

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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
(R)-warfarin
The serum concentration of (R)-warfarin can be increased when it is combined with Citalopram.
(S)-Warfarin
The serum concentration of (S)-Warfarin can be increased when it is combined with Citalopram.
1-(2-Phenylethyl)-4-phenyl-4-acetoxypiperidine
The metabolism of Citalopram can be decreased when combined with 1-(2-Phenylethyl)-4-phenyl-4-acetoxypiperidine.
2,4-thiazolidinedione
The risk or severity of hypoglycemia can be increased when Citalopram is combined with 2,4-thiazolidinedione.
2,5-Dimethoxy-4-ethylamphetamine
The risk or severity of serotonin syndrome can be increased when Citalopram is combined with 2,5-Dimethoxy-4-ethylamphetamine.
2,5-Dimethoxy-4-ethylthioamphetamine
The risk or severity of adverse effects can be increased when 2,5-Dimethoxy-4-ethylthioamphetamine is combined with Citalopram.
3,5-diiodothyropropionic acid
The therapeutic efficacy of 3,5-diiodothyropropionic acid can be decreased when used in combination with Citalopram.
3,5-Diiodotyrosine
The therapeutic efficacy of 3,5-Diiodotyrosine can be decreased when used in combination with Citalopram.
4-Bromo-2,5-dimethoxyamphetamine
The risk or severity of adverse effects can be increased when Citalopram is combined with 4-Bromo-2,5-dimethoxyamphetamine.
4-hydroxycoumarin
The risk or severity of hemorrhage can be increased when Citalopram is combined with 4-hydroxycoumarin.
4-Methoxyamphetamine
The risk or severity of adverse effects can be increased when Citalopram is combined with 4-Methoxyamphetamine.
5-methoxy-N,N-dimethyltryptamine
The risk or severity of adverse effects can be increased when 5-methoxy-N,N-dimethyltryptamine is combined with Citalopram.
6-O-benzylguanine
The metabolism of 6-O-benzylguanine can be decreased when combined with Citalopram.
7-Nitroindazole
The risk or severity of adverse effects can be increased when Citalopram is combined with 7-Nitroindazole.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline
The risk or severity of serotonin syndrome can be increased when 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline is combined with Citalopram.
8-azaguanine
The metabolism of 8-azaguanine can be decreased when combined with Citalopram.
8-chlorotheophylline
The metabolism of 8-chlorotheophylline can be decreased when combined with Citalopram.
9-aminocamptothecin
The metabolism of 9-aminocamptothecin can be decreased when combined with Citalopram.
9-Deazaguanine
The metabolism of 9-Deazaguanine can be decreased when combined with Citalopram.
9-Methylguanine
The metabolism of 9-Methylguanine can be decreased when combined with Citalopram.
19 References
  1. 1 . Sindrup SH, Bjerre U, Dejgaard A, Brosen K, Aaes-Jorgensen T, Gram LF: The selective serotonin reuptake inhibitor citalopram relieves the symptoms of diabetic neuropathy. Clin Pharmacol Ther. 1992 Nov;52(5):547-52.PubMed: 1424428
  2. 2 . Atmaca M, Kuloglu M, Tezcan E, Semercioz A: The efficacy of citalopram in the treatment of premature ejaculation: a placebo-controlled study. Int J Impot Res. 2002 Dec;14(6):502-5.PubMed: 12494286
  3. 3 . Andersen G, Vestergaard K, Riis JO: Citalopram for post-stroke pathological crying. Lancet. 1993 Oct 2;342(8875):837-9.PubMed: 8104273
  4. 4 . Clayton A, Keller A, McGarvey EL: Burden of phase-specific sexual dysfunction with SSRIs. J Affect Disord. 2006 Mar;91(1):27-32. Epub 2006 Jan 20.PubMed: 16430968
  5. 5 . Baumann P: Pharmacology and pharmacokinetics of citalopram and other SSRIs. Int Clin Psychopharmacol. 1996 Mar;11 Suppl 1:5-11.PubMed: 8732438
  6. 6 . Caccia S: Metabolism of the newer antidepressants. An overview of the pharmacological and pharmacokinetic implications. Clin Pharmacokinet. 1998 Apr;34(4):281-302.PubMed: 9571301
  7. 7 . Bezchlibnyk-Butler K, Aleksic I, Kennedy SH: Citalopram--a review of pharmacological and clinical effects. J Psychiatry Neurosci. 2000 May;25(3):241-54.PubMed: 10863884
  8. 8 . Keller MB: Citalopram therapy for depression: a review of 10 years of European experience and data from U.S. clinical trials. J Clin Psychiatry. 2000 Dec;61(12):896-908.PubMed: 11206593
  9. 9 . Sheeler RD, Ackerman MJ, Richelson E, Nelson TK, Staab JP, Tangalos EG, Dieser LM, Cunningham JL: Considerations on safety concerns about citalopram prescribing. Mayo Clin Proc. 2012 Nov;87(11):1042-5. doi: 10.1016/j.mayocp.2012.07.009. Epub 2012 Sep 24.PubMed: 23018033
  10. 10 . Naranjo CA, Knoke DM, Bremner KE: Variations in response to citalopram in men and women with alcohol dependence. J Psychiatry Neurosci. 2000 May;25(3):269-75.PubMed: 10863887
  11. 11 . Thomsen PH: Child and adolescent obsessive-compulsive disorder treated with citalopram: findings from an open trial of 23 cases. J Child Adolesc Psychopharmacol. 1997;7(3):157-66. doi: 10.1089/cap.1997.7.157.PubMed: 9466233
  12. 12 . McElroy SL, Hudson JI, Malhotra S, Welge JA, Nelson EB, Keck PE Jr: Citalopram in the treatment of binge-eating disorder: a placebo-controlled trial. J Clin Psychiatry. 2003 Jul;64(7):807-13.PubMed: 12934982
  13. 13 . Sangkuhl K, Klein TE, Altman RB: PharmGKB summary: citalopram pharmacokinetics pathway. Pharmacogenet Genomics. 2011 Nov;21(11):769-72. doi: 10.1097/FPC.0b013e328346063f.PubMed: 21546862
  14. 14 . https://www.ncbi.nlm.nih.gov/books/NBK482222/ (2018). Stat Pearls [Internet]. NIH Stat Pearls.
  15. 15 . MSDS citalopram Link
  16. 16 . NIH Stat Pearls: Citalopram Link
  17. 17 . AAFP: Off-label Applications for SSRIs Link
  18. 18 . Celexa Information, FDA Link
  19. 19 . Celexa Monograph File