No interaction between raltegravir and oral contraceptives
A placebo-controlled, randomised, two-period crossover study in 19 healthy HIV-seronegative women was conducted to assess the effect of raltegravir (400 mg twice daily) on the pharmacokinetics of an oral contraceptive containing ethinylestradiol and norgestimate.
The geometric mean ratio (GMR) and 90% confidence interval (CI) for ethinylestradiol when co-administrated with raltegravir relative to alone was 0.98 (0.931.04) for AUC and 1.06 (0.981.14) for Cmax. The GMR (90% CI) for norelgestromin (an active metabolite of norgestimate) when co-administered with raltegravir relative to alone was 1.14 (1.081.21) for AUC and 1.29 (1.231.37) for Cmax. There were no discontinuations due to a study drug-related adverse experience, nor any serious clinical or laboratory adverse experience.
Raltegravir had no clinically important effect on ethinylestradiol or norgestimate pharmacokinetics and no dose adjustment is required for oral contraceptives containing this combination when co-administered with raltegravir.
www.HIV-druginteractions.org (24 March 2011).
Anderson MS et al. Effect of raltegravir on estradiol and norgestimate plasma pharmacokinetics following oral contraceptive administration in healthy women. Br J Clin Pharmacol, 2011, 71(4): 616-620.