Most HIV drugs have little or no impact on the effectiveness of hormonal contraceptives, according to a 46-study analysis. A possible exception is the drug Sustiva (efavirenz, Stocrin, contained in Atripla), which may limit the effectiveness of implants and combined oral contraceptive pills, but the link is not very strong.
Many women throughout the world take antiretroviral therapy to treat HIV, and some take one or more antiretrovirals to prevent HIV transmission. Understanding how antiretrovirals interact with hormonal contraceptives is critical: Antiretrovirals may lower contraceptive levels in the body and make them less effective, and contraceptives may affect levels of antiretrovirals.
To determine whether taking antiretrovirals and hormonal contraceptives at the same time affects safety or effectiveness, researchers searched three online databases for all studies of contraceptive-antiretroviral interactions through September 2015. Women in these studies used any form of hormonal contraceptive, including combined oral contraceptive pills, implants, or long-term injected agents like Depo-Provera. The types of antiretrovirals analyzed were nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors, entry inhibitors, and integrase inhibitors -- all common classes of HIV drugs.
The final analysis included 50 published reports of 46 individual studies. Review of these studies revealed only limited interactions between most antiretrovirals and hormonal contraceptives.
The study found possible interactions between Sustiva and two types of hormonal contraceptive-- implants and combined oral contraceptive pills --but not between Sustiva and injected contraceptives including Depo-Provera. In two large studies, pregnancy rates were slightly higher in women taking Sustiva and oral contraceptives than in women taking another nonnucleoside or no antiretrovirals, though these rates were still lower than would be expected in women using no contraception. In two studies of women using contraceptive implants, pregnancy rates were higher in women taking Sustiva with an implant containing levonorgestrel, but not in women taking Sustiva with an implant containing etonogestrel. In another study, pregnancy rates were higher when either implant was combined with Sustiva than with either the nonnucleoside Viramune (nevirapine) or no antiretroviral.
Hormonal contraceptives did not affect levels or effectiveness of the antiretrovirals studied.
The researchers conclude that "the most significant interactions with hormonal contraceptives" occurred in women using nonnucleosides, particularly Sustiva. Even in those studies, evidence did not strongly suggest Sustiva makes hormonal agents less effective. But the authors note that effectiveness of combined oral contraceptive pills depends on steady pill-taking by the women. So any decrease in pill effectiveness due to Sustiva would be concerning.
The many other studies of potential interactions between other antiretrovirals and hormonal contraceptives "reported no results that should change clinical practice." The analysis also showed that antiretrovirals taken as pre-exposure prophylaxis (PrEP) to prevent HIV infection "do not affect hormonal contraceptive effectiveness." Overall, the researchers conclude women taking antiretrovirals for HIV treatment or prevention "should have access to the full range of hormonal contraceptive options."