Efavirenz, in contrast to nevirapine, is associated with unfavorable progesterone and antiretroviral levels when coadministered with combined oral contraceptives

J Acquir Immune Defic Syndr. 2013 Apr 15;62(5):534-9. doi: 10.1097/QAI.0b013e31827e8f98.

Abstract

Background: Effective contraception has been widely promoted for HIV-positive women. However, there are limited data on the interactions between combined hormonal contraceptives and nonnucleoside reverse transcriptase inhibitors .

Methods: This study assessed the steady-state contraceptive effectiveness and safety of combined oral contraceptive (COC) containing 0.150 mg desogestrel /0.030 mg ethinyl estradiol with either nevirapine (NVP) or efavirenz (EFV) in 34 HIV-positive women. The targeted level for contraceptive effectiveness was endogenous progesterone level < 3.0 ng/mL. We measured NVP/EFV plasma concentrations 12 hours after administration (C12) with and without COC. The desired therapeutic levels were >3.1 mg/L for NVP and 1.0-4.0 mg/L for EFV, respectively.

Results: All 18 subjects in the NVP group had serum progesterone <1.0 ng/mL. Four of 16 subjects (25%) in the EFV group had serum progesterone >1.0 ng/mL, including 3 subjects with >3.0 ng/mL (might indicate ovulation). The difference in progesterone levels between the 2 groups was statistically significant (P = 0.04). The median C12 of NVP increased insignificantly by 17% with COC; the median C12 of EFV decreased significantly (P = 0.02) by 22%. In 3 of 16 subjects (19%) in the EFV group, C12 of EFV dropped below 1.0 mg/L.

Conclusions: In contrast to NVP, coadministrating desogestrel/ethinyl estradiol containing COC with EFV was associated with unfavorable progesterone and antiretroviral levels. Our results suggest that NVP may be superior to EFV when used with COC in HIV-positive women.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alkynes
  • Anti-HIV Agents / administration & dosage
  • Anti-HIV Agents / adverse effects
  • Anti-HIV Agents / blood
  • Benzoxazines / administration & dosage*
  • Benzoxazines / blood
  • Contraceptives, Oral, Synthetic / administration & dosage*
  • Cyclopropanes
  • Desogestrel / administration & dosage
  • Drug Interactions
  • Ethinyl Estradiol / administration & dosage
  • Female
  • HIV / isolation & purification
  • HIV Infections / blood*
  • HIV Infections / drug therapy*
  • Humans
  • Logistic Models
  • Middle Aged
  • Nevirapine / administration & dosage*
  • Nevirapine / adverse effects
  • Nevirapine / blood
  • Progesterone / blood*
  • Prospective Studies
  • Thailand
  • Young Adult

Substances

  • Alkynes
  • Anti-HIV Agents
  • Benzoxazines
  • Contraceptives, Oral, Synthetic
  • Cyclopropanes
  • Ethinyl Estradiol
  • Progesterone
  • Desogestrel
  • Nevirapine
  • efavirenz