Citalopram - A review of its pharmacology, clinical efficacy and tolerability in the treatment of depression

Citalopram is a selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor (SSRI) which has been evaluated primarily in the treatment of major depression. In well controlled short term studies, citalopram had efficacy similar to that of a number of but not all, tricyclic or tetracyclic antidepressants and was as effective as fluoxetine and fluvoxamine. There is some evidence of a faster onset of action for citalopram compared with fluoxetine. Initial data suggest that citalopram is effective in the prevention of depressive relapse and in the treatment of post-stroke depression. The anticholinergic and cardiovascular adverse events often seen with tricyclic antidepressants generally occur less frequently or are infrequent with citalopram, as with other SSRIs. Citalopram has been well tolerated in the elderly and in patients with existing cardiovascular disease. In vitro and in vivo pharmacodynamic studies suggest that citalopram is a weak inhibitor of cytochrome P450 (CYP) 2D6, and data from several interaction studies in patients and healthy volunteers are consistent with this finding. Thus, citalopram is an effective and well tolerated SSRI which, like the other members of its class, represents a suitable first-line therapy for major depression. Additional efficacy data would be beneficial in clarifying the potential of citalopram in the elderly and in patients with post-stroke depression or preexisting cardiovascular disorders, for whom anticholinergic or cardiovascular adverse events (caused by tricyclic antidepressants) are a serious concern. The main distinguishing feature of citalopram within its class is its apparent low propensity to cause problematic drug interactions with CYP2D6 substrates; these include a number of commonly prescribed drug classes, such as antipsychotics, tricyclic antidepressants, antiarrhythmics and beta-blockers. Thus, citalopram may prove useful in the many patients with depression who require one or more such agents for treatment of additional psychiatric or general disorders.