Antiretroviral Therapy Not Likely to Interfere with Effectiveness of Popular Contraceptive

Results of a clinical trial by scientists at Family Health International and the Universidade Estadual de Campinas, in Brazil, suggest that combination antiretroviral (ARV) therapy is not likely to affect the contraceptive effectiveness of the injectable depot medroxyprogesterone acetate (DMPA).

The study, which was conducted with partial support from USAID, enrolled 30 HIV-infected women. Half of the women were using efavirenz-based triple therapy, which contains the drugs zidovudine (AZT), lamivudine (3TC), and efavirenz (EFV). Half of the women were using no ARV drugs. All of the women received a single injection of DMPA and were followed for 12 weeks.

Analysis of blood samples (taken before the women received DMPA and then at regular intervals throughout the study) found that the pharmacokinetics of DMPA were similar for both groups. In addition, none of the women using both DMPA and ARV drugs ovulated.

Efavirenz-based triple therapy is common, so these findings have important implications. Because HIV often affects young women who have many reproductive years ahead of them, women who are being treated for HIV need access to safe and reversible contraceptives, including DMPA. The use of highly effective contraception by HIV-infected women who do not want to become pregnant is also a key strategy for preventing mother-to-child transmission of HIV.

Source
Nanda K, Amaral E, Hays M, Viscola MAM, Mehta N, Bahamondes L. Pharmacokinetic interactions between depot medroxyprogesterone acetate and combination antiretroviral therapy. Fertility and Sterility, 2008; (90) 4: 965-971.