Abstract
Objectives: The primary objective of this study was to characterize the pharmacokinetics of etonogestrel (ENG) released from a contraceptive implant in Ugandan women living with HIV who were receiving efavirenz (EFV) or nevirapine (NVP)-based antiretroviral therapy (ART), compared with ART-naive women over 24 weeks. Design: Nonrandomized, parallel-group study with three arms: ART-naive, NVP, or EFV-based ART (N==20/group). Methods: Sparse pharmacokinetic sampling of ENG, NVP, or EFV were performed at screening, entry, and then 1, 4, 12, and 24-week postimplant insertion. The primary endpoint was ENG concentrations at week 24, compared between the ART-naive group and each ART group, using geometric mean ratio (GMR) with 90% confidence intervals. Results: Sixty participants competed the 24-week study and data from 58 participants are included; one participant each was excluded from the NVP group and EFV group because of a sample processing error and ART nonadherence, respectively. At week 24, geometric mean ENG was 362, 341, and 66=pg/ml in the ART-naive, NVP, and EFV groups, respectively [GMR: NVP=:ART-naive 0.94 (0.90-1.01); EFV=:ART-naive 0.18 (0.17-0.20)]. NVP and EFV concentrations were lower at week 24 compared to preimplant [NVP: geometric mean 5.7 versus 6.8=mg/l, respectively, GMR 0.84 (0.83-0.85); EFV: geometric mean 3.6 versus 4.9=mg/l, respectively, GMR 0.73 (0.69-0.80)]. Conclusion: After 24 weeks of combined use, ENG exposure was 82% lower in women using EFV-based ART compared with ART-naive women. In contrast, NVP did not significantly impact ENG exposure. These results raise concerns about reduced effectiveness of implantable contraception for women taking EFV-based ART.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1965-1972 |
| Number of pages | 8 |
| Journal | AIDS |
| Volume | 31 |
| Issue number | 14 |
| DOIs | |
| State | Published - Sep 10 2017 |
Funding
The authors gratefully acknowledge the contributions of the women who participated in this study and express sincere appreciation to the members of the study team including Isabella Kyohairwe, Frank Mubiru, and Henry Onen. C.A.C., K.K.S., M.L., S.N., S.L.A., B.A.C., S.E.C., S.A.R., and K.M.D. were involved with conception and design. S.N., M.L., C.A.C., S.L.A., B.A.C., and H.M. were involved with performance of the study. C.A.C. performed the descriptive statistics and K.K.S. preformed the pharmacokinetic analysis. C.A.C. drafted the manuscript. K.K.S., M.L., S.L.A., B.A.C., S.E.C., K.M.D., and S.A.R. edited the text. All authors have read the manuscript and approved the text. The study was supported by the Society of Family Planning Research Fund grant #SFPRF14-12 and by the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health 5R21HD074462 and 1R01HD085887 (Scarsi) and by NIH/ORWH Building Interdisciplinary Research Careers in Women's Health (BIRCWH) NIH K12HD043441 to Chappell. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Keywords
- antiretroviral therapy
- contraceptive implant
- drug-drug interaction
- efavirenz
- etonogestrel
- family planning
- nevirapine
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology
- Infectious Diseases
