This article reviews
escitalopram, the S-stereoisomer of the racemic compound
citalopram, and a highly selective and potent member of the selective
serotonin re-uptake inhibitor class of
antidepressants.
Escitalopram has a straightforward pharmacokinetic profile, little effect on hepatic metabolism, and is relatively safe in overdose. Similar to other members of the selective
serotonin re-uptake inhibitor class,
escitalopram (10-20 mg/day) is a well-tolerated and effective treatment of
major depressive disorder. Although relatively few head-to-head comparative studies with other
antidepressants have been published, pooled analyses of studies using
citalopram as the active comparator suggest a modest advantage for the stereoisomer. This advantage, which is more apparent among patients with greater symptom levels, may be attributable to a greater than predicted potency compared with
citalopram, presumably as a result of the greater effect of
escitalopram at the allosteric binding site of the
serotonin transporter. Results of two published studies versus
venlafaxine also suggest better tolerability in the context of comparable efficacy.
Escitalopram is also approved for the treatment of generalised
anxiety disorder (in the US) and
social anxiety disorder and
panic disorder (in the EU). Pharmacoeconomic models suggest that the greater drug acquisition cost of this patent-protected compound may be offset by greater efficacy (relative to generic
citalopram) and tolerability (compared with extended release
venlafaxine).