Citation noticeOur citation system is being overhauled
References and citation markers may currently be incomplete, mismatched, or incorrect. This system is being rebuilt and reviewed before the full site launch.
Citalopram
Citalopram is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class1 and an organic phenylbutylamine. It is a racemic bicyclic phthalate derivative distinguished among SSRIs by its tertiary amine and high selectivity for serotonin reuptake inhibition. In patients with bipolar disorder, treatment of a depressive episode with citalopram tablets or another antidepressant may precipitate a mixed or manic episode1.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Subjective Effects
Pharmacology
Pharmacodynamics
In vitro and in vivo animal studies suggest that citalopram selectively inhibits serotonin reuptake.2 In vitro and in vivo animal studies suggest minimal effects on norepinephrine and dopamine neuronal reuptake; citalopram has no or very low affinity for muscarinic cholinergic, histamine H1, GABA, α1-, α2- and β-adrenergic, and dopamine D1 and D2 receptors.2 Citalopram is a racemic mixture: (S)-citalopram is the more potent SERT inhibitor, while (R)-citalopram is substantially less potent and may antagonize some (S)-citalopram activity at SERT; the mechanism of this interaction is uncertain. Both citalopram and escitalopram bind the sigma-1 receptor with similar affinity, although the functional significance is not established.
Pharmacokinetics
Citalopram has linear, dose-proportional pharmacokinetics over 10–40 mg/day.2 After an oral dose, peak blood levels occur at about 4 hours, absolute bioavailability is approximately 80% relative to intravenous dosing, and absorption is unaffected by food.2 It is distributed extensively, with a volume of distribution of about 12 L/kg, and approximately 80% is bound to plasma proteins.2 Biotransformation is mainly hepatic, principally by N-demethylation through CYP2C19 and CYP3A4, with additional CYP2D6 metabolism and oxidation involving monoamine oxidases A and B and aldehyde oxidase. Citalopram undergoes mainly hepatic biotransformation2 and has a mean terminal half-life of about 35 hours;2 with once-daily dosing, steady-state plasma concentrations are achieved within approximately one week.2 Following intravenous administration, approximately 20% of systemic clearance was due to renal clearance.2 Elimination is slower in older adults and in people with hepatic or renal impairment.
Interactions
An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.
Tolerance
Harm Potential
Addiction & Dependence
Psychological
LowCitalopram does not produce euphoria or a high and is not typically associated with abuse potential or compulsive use patterns. However, discontinuation syndrome upon stopping treatment indicates some degree of neuroadaptation.
Physical
ModerateSSRI discontinuation syndrome is well-documented and includes sensory disturbances, electric shock-like sensations, gastrointestinal symptoms, dizziness, lethargy, sleep disturbances, anxiety, agitation, irritability, and poor concentration. Treatment should be reduced gradually when discontinued.
Toxicity
Citalopram causes dose-dependent QT interval prolongation and is associated with a higher risk of arrhythmia than other SSRIs; doses above 40 mg daily are no longer recommended, with a maximum of 20 mg for those over 60 years old.
Rare side effects include convulsions and hallucinations; seizures may occur in overdose and can be delayed. Visual snow syndrome has been reported as a rare side effect that may not resolve after discontinuation.
Mating and fertility were decreased in animal studies at doses approximately 8 times the maximum recommended human dose.
In a 24-month rat study, small-intestine carcinomas occurred more often at exposures roughly twofold and sixfold higher than the maximum recommended dose for humans.
In a 24-month rat study, citalopram was associated with more small-intestine carcinomas. It was also mutagenic in 2 of 5 bacterial reverse-mutation assay strains and clastogenic in the Chinese hamster lung cell chromosomal-aberration assay.
Psychosis Risk
Hallucinations are a rare side effect. Citalopram, like other SSRIs, may provoke manic or mixed symptoms, with particular concern for people whose bipolar disorder has not been diagnosed.
Seizure Risk
Convulsions are listed as a rare side effect. Seizures may occur in overdose and can be delayed in onset.
History & Culture
Legality
By Country
United StatesPrescription only
CanadaPrescription onlyReferences
Citations
Article Status
Step 1 · Automated synthesisAn autonomous workflow built by Josie Kins compiled this article's foundation from information published across the web.
- Step 2 · First-pass reviewPending
Not yet reviewed: this article is pending editorial review by Lyrea.
- Step 3 · Citation reviewPending
No one has reviewed this article's citations yet. That second pass checks each claim against the source it cites.
Suggest an edit
Spotted a mistake, an outdated claim, or something missing from the Citalopram article? Send the editors a private note. Feedback lands in a moderation queue and is never shown on the site.
Wish to give generalised feedback? You can do so here.
