Conference Coverage

Efavirenz-based ART may hamper vaginal ring contraception

 

Key clinical point: Some anti-HIV agents may interfere with the efficacy of hormone-based contraceptives.

Major finding: Estrogen exposure in women on efavirenz was 53%-57% lower than among controls.

Study details: A pharmacokinetic study in 74 HIV-infected women.

Disclosures: The study was supported by the National Institutes of Health. Merck provided the vaginal ring used in the study. Dr. Scarsi reported having no conflicts of interest to disclose.

Source: Scarsi KK et al. CROI 2018, Abstract 141.


 

REPORTING FROM CROI 2018

– Efavirenz-based antiretroviral therapy may significantly impair the effectiveness of vaginal ring contraceptives, investigators reported.

Over a 21-day period, levels of estrogen among women who used a vaginal ring (NuvaRing) while on efavirenz-based antiretroviral therapy (ART) were up to 79% lower, and levels of progestin were up to 57% lower, than in women with HIV infection who used the vaginal ring before starting ART, reported Kimberly K. Scarsi, PharmD, of the University of Nebraska, Omaha.

In contrast, women on an atazanavir-based ART regimen had lower estrogen levels than untreated controls who used a vaginal ring, but higher levels of progestin – the primary antiovulatory component of the ring – suggesting that it would retain contraceptive effectiveness, she said at the annual Conference on Retroviruses and Opportunistic Infections.

“In a broader context, these data can be applied to other drugs that behave similarly. So for example, erythromycins are also known to interfere with hormones in this way, as well as some anticonvulsant agents that may also impair the effectiveness of vaginal ring contraceptives,” she said at a brief, following her presentation of the data in an oral abstract session.

Pages

Next Article:

   Comments ()