Effect of prucalopride on the pharmacokinetics of oral contraceptives in healthy women.

backgroundPrucalopride is a selective, high-affinity, 5-hydroxytryptamine 4 (5-HT4) receptor agonist, which is approved for the symptomatic treatment of chronic constipation in women in whom laxatives fail to provide adequate relief. Women of childbearing potential, many of whom will be using oral contraceptives, comprise a large proportion of patients seeking medical therapy for constipation.

objectiveThe aim of this study was to evaluate the effect of prucalopride on the absorption and steady-state pharmacokinetics of oral contraceptives in healthy women.

methodsSixteen women (aged 18-45 years) were enrolled in this open-label, two-way crossover trial (ClinicalTrials.gov identifier: NCT01036893) and given two 5-day treatments with a once-daily oral contraceptive (ethinylestradiol 0.035 mg + norethisterone 1 mg), alone and in combination with prucalopride 2 mg once daily. Treatments were separated by a 7 ± 2-day washout period. On days 1 and 5, blood samples were obtained pre-dose and at regular intervals post-dose up to 24 and 48 hours, respectively, to determine ethinylestradiol and norethisterone plasma concentrations. Prucalopride plasma concentrations were determined pre-dose and 3 hours post-dose on days 1 and 5, and 24 hours post-dose on day 6. Safety was assessed.

resultsThirteen participants completed the study. One participant was thought to be non-compliant on days 3 and/or 4, and was excluded from the day 5 analysis. On days 1 and 5, maximum plasma concentrations of both oral contraceptive constituents were attained in ~1 hour and were unaffected by prucalopride administration. On day 5, steady-state prucalopride and oral contraceptive concentrations had been achieved. Prucalopride did not affect the pharmacokinetics of the oral contraceptives: point estimates for the maximum plasma concentration and area under the plasma concentration-time curve values and their associated 90 % confidence intervals were contained within predefined equivalence limits (80-125 %). Prucalopride was well tolerated, with a safety profile consistent with those observed in previous studies.

conclusionCo-administration of prucalopride with an oral contraceptive did not result in any clinically meaningful pharmacokinetic interactions and was well tolerated.