Pharmacokinetic interaction between nevirapine and ethinyl estradiol/norethindrone when administered concurrently to HIV-infected women
Mildvan, D.; Yarrish, R.; Marshak, A.; Hutman, H.W.; McDonough, M.; Lamson, M.; Robinson, P.
Journal of Acquired Immune Deficiency Syndromes 29(5): 471-477
2002
ISSN/ISBN: 1525-4135 PMID: 11981363 DOI: 10.1097/00126334-200204150-00007Document Number: 242161
Objective: To determine the effects of nevirapine (NVP), a nonnucleoside reverse-transcriptase inhibitor of HIV-1 and P450 inducer, on the pharmacokinetics (PK) of ethinyl estradiol (EE)/norethindrone (NET), a widely used oral contraceptive, and to assess the effects of EE/NET on the steady-state PK of NVP. Methods: Ten HIV-1-infected women underwent intensive PK sampling after single-dose administration of EE/NET (days 0-1). Oral NVP 200 mg once daily (days 2-15), followed by 200 mg twice daily (days 16-29), was added to background potent antiretroviral therapy. On day 30, intensive PK sampling was performed after concurrent administration of NVP 200 mg and a single dose of EE/NET. Results: Concomitant administration of NVP at steady state with EE/NET resulted in a significant (29%) median reduction in the area under the plasma concentration time curve (AUC infinity ) and a significant reduction in mean residence time (MRT) and half-life (t1/2) of EE. There was a significant (18%) median reduction in the AUC infinity for NET that was not associated with a detectable change in NET Cmax, MRT, or t1/2. Conclusion: Oral contraceptives should not be the primary method of birth control in women of child-bearing potential who are treated with NVP.