title: Effect of antiretroviral therapy including lopinavir/ritonavir or efavirenz on etonogestrel-releasing implant pharmacokinetics in HIV-positive women.
abstract: OBJECTIVE
  Data on the interaction between the etonogestrel (ENG) implant and antiretroviral therapy are lacking. We evaluated the effect of 2 highly active antiretroviral therapy (HAART) regimens (1 including efavirenz and the other ritonavir-boosted lopinavir) on the pharmacokinetic (PK) parameters of an ENG-releasing implant in HIV-positive women.
  
  
  METHODS
  Prospective nonrandomized PK study.
  
  
  METHODS
  Forty-five HIV-positive women who desired to use ENG implants were included: 15 had received zidovudine/lamivudine + lopinavir/ritonavir for ≥3 months (LPV/r-based HAART group), 15 had received zidovudine/lamivudine + efavirenz for ≥3 months (EFV-based HAART group), and 15 had not received HAART (non-HAART group). PK parameters were measured using ultra-performance liquid chromatography-mass spectrometry at baseline and 2, 4, 6, 8, 10, 12, 16, 20, and 24 weeks after implant placement.
  
  
  RESULTS
  The EFV-based HAART regimen was associated with a reduction in the bioavailability of ENG, which showed decreases of 63.4%, 53.7%, and 70% in the area under the curve (AUC), maximum concentration (Cmax), and minimum concentration (Cmin) of ENG, respectively, compared with the non-HAART group. The LPV/r-based HAART regimen was associated with an increase in ENG bioavailability, which showed 52%, 60.6%, and 33.8% increases in the ENG AUC, Cmax, and Cmin, respectively, compared with the non-HAART group.
  
  
  CONCLUSIONS
  The coadministration of EFV decreased the bioavailability of ENG released from the implant, which could impair contraceptive efficacy. However, the coadministration of LPV/r increased the bioavailability of ENG released from the implant, which suggests that this antiretroviral combination does not impair the ENG implant efficacy.
authors.affiliation: *Department of Gynecology and Obstetrics, Medical School of Ribeirao Preto, University of São Paulo, São Paulo, Brazil. Avenida Bandeirantes, Ribeirão Preto, São Paulo, Brazil; †National Institute of Hormones and Women's Health, Brazil; ‡Department of Obstetrics and Gynecology, Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; §Federal Technological University of Paraná, Campus Cornélio Procópio, Brazil. Avenida Alberto Carazzai, Cornélio Procópio, Paraná, Brazil; and ‖Department of Gynecology and Obstetrics, Federal University of Bahia. R. Augusto Viana, 1-Canela, CEP: 40110-060, Salvador, Bahia, Brazil.
authors.forename: Carolina S
authors.initials: CS
authors.lastname: Vieira
authors.forename: Maria V
authors.initials: MV
authors.lastname: Bahamondes
authors.forename: Roberto M
authors.initials: RM
authors.lastname: de Souza
authors.forename: Milena B
authors.initials: MB
authors.lastname: Brito
authors.forename: Tatiana R
authors.initials: TR
authors.lastname: Rocha Prandini
authors.forename: Eliana
authors.initials: E
authors.lastname: Amaral
authors.forename: Luis
authors.initials: L
authors.lastname: Bahamondes
authors.forename: Geraldo
authors.initials: G
authors.lastname: Duarte
authors.forename: Silvana M
authors.initials: SM
authors.lastname: Quintana
authors.forename: Carolina
authors.initials: C
authors.lastname: Scaranari
authors.forename: Rui A
authors.initials: RA
authors.lastname: Ferriani
mesh_terms: D000328:Adult; D000480:Alkynes; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D048588:Benzoxazines / Q000627:therapeutic use*; D001682:Biological Availability; D003271:Contraceptive Agents, Female / Q000493:pharmacokinetics; D003521:Cyclopropanes; D017135:Desogestrel / Q000493:pharmacokinetics*; D004338:Drug Combinations; D004343:Drug Implants; D004347:Drug Interactions; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D061466:Lopinavir / Q000627:therapeutic use*; D019438:Ritonavir / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003271:Contraceptive Agents, Female; D003521:Cyclopropanes; D004338:Drug Combinations; D004343:Drug Implants; C558899:lopinavir-ritonavir drug combination; D061466:Lopinavir; C044815:etonogestrel; D017135:Desogestrel; C098320:efavirenz; D019438:Ritonavir