The effect of cimetidine or omeprazole on the pharmacokinetics of escitalopram in healthy subjects
Article first published online: 29 JUN 2005
British Journal of Clinical Pharmacology
Volume 60, Issue 3, pages 287–290, September 2005
How to Cite
Malling, D., Poulsen, M. N. and Søgaard, B. (2005), The effect of cimetidine or omeprazole on the pharmacokinetics of escitalopram in healthy subjects. British Journal of Clinical Pharmacology, 60: 287–290. doi: 10.1111/j.1365-2125.2005.02423.x
- Issue published online: 29 JUN 2005
- Article first published online: 29 JUN 2005
- Received 26 November 2004 Accepted 28 January 2005
- drug interactions;
To investigate the effects of co-administration of cimetidine or omeprazole on the pharmacokinetics of escitalopram.
Two randomized placebo-controlled crossover studies were carried out. Sixteen healthy subjects were administered placebo, or cimetidine (400 mg twice daily) for 5 days (study 1) or omeprazole (30 mg once daily) for 6 days (study 2). On day 4 (study 1) or day 5 (study 2), a single dose of escitalopram (20 mg) was administered. Blood samples were taken at predetermined times for the measurement of serum concentrations of escitalopram and its demethylated metabolite (S-DCT). Treatment-emergent adverse events were also monitored.
Co-administration with cimetidine caused a moderate increase in the systemic exposure [AUC(0, ∞)] to escitalopram (geometric mean ratio = 1.72, [95% CI 1.34, 2.21]) and a small increase in t½ from 23.7 to 29.0 h (5.24 h [3.75, 6.70]). Co-administration with omeprazole also resulted in a moderate increase in the escitalopram AUC(0, ∞) (1.51 [1.39, 1.64]) and a small increase in t½ from 26.5 to 34.8 h (8.3 h [6.44, 10.2]). There was no significant change in S-DCT AUC(0, ∞) after co-administration of either cimetidine or omeprazole. Co-administration of cimetidine or omeprazole had no effect on the incidence of treatment-emergent adverse events.
In view of the good tolerability of escitalopram, the pharmacokinetic changes observed on co-administration with cimetidine or omeprazole are unlikely to be of clinical concern.