title: Efavirenz, in contrast to nevirapine, is associated with unfavorable progesterone and antiretroviral levels when coadministered with combined oral contraceptives.
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.
authors.affiliation: The HIV Netherlands Australia Thailand Research Collaboration (HIV-NAT), Bangkok, Thailand.
authors.forename: Nadia Kancheva
authors.initials: NK
authors.lastname: Landolt
authors.forename: Nittaya
authors.initials: N
authors.lastname: Phanuphak
authors.forename: Sasiwimol
authors.initials: S
authors.lastname: Ubolyam
authors.forename: Suteeraporn
authors.initials: S
authors.lastname: Pinyakorn
authors.forename: Rosalin
authors.initials: R
authors.lastname: Kriengsinyot
authors.forename: Jennisa
authors.initials: J
authors.lastname: Ahluwalia
authors.forename: Parawee
authors.initials: P
authors.lastname: Thongpaeng
authors.forename: Meena
authors.initials: M
authors.lastname: Gorowara
authors.forename: Narukjaporn
authors.initials: N
authors.lastname: Thammajaruk
authors.forename: Surasith
authors.initials: S
authors.lastname: Chaithongwongwatthana
authors.forename: Joep M A
authors.initials: JM
authors.lastname: Lange
authors.forename: Jintanat
authors.initials: J
authors.lastname: Ananworanich
mesh_terms: D000293:Adolescent; D000328:Adult; D000480:Alkynes; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood; D048588:Benzoxazines / Q000008:administration & dosage* / Q000097:blood; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage*; D003521:Cyclopropanes; D017135:Desogestrel / Q000008:administration & dosage; D004347:Drug Interactions; D004997:Ethinyl Estradiol / Q000008:administration & dosage; D005260:Female; D006678:HIV / Q000302:isolation & purification; D015658:HIV Infections / Q000097:blood* / Q000188:drug therapy*; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D019829:Nevirapine / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D011374:Progesterone / Q000097:blood*; D011446:Prospective Studies; D013785:Thailand; D055815:Young Adult
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003280:Contraceptives, Oral, Synthetic; D003521:Cyclopropanes; D004997:Ethinyl Estradiol; D011374:Progesterone; D017135:Desogestrel; D019829:Nevirapine; C098320:efavirenz