Kreitchmann R, Stek A, Best BM, Capparelli E, Wang J, Shapiro D, Chakhtoura N, Mirochnick M, Eke AC. Interactions between etonogestrel-releasing contraceptive implant and 3 antiretroviral regimens.
Contraception 2022;
105:67-74. [PMID:
34407424 PMCID:
PMC8678338 DOI:
10.1016/j.contraception.2021.08.006]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVES
Long-acting reversible contraceptives are effective contraceptives for women with HIV, but there are limited data on etonogestrel implant and antiretroviral therapy pharmacokinetic drug-drug interactions. We evaluated etonogestrel/antiretroviral therapy drug-drug interactions, and the effects of etonogestrel on ritonavir-boosted-atazanavir, ritonavir-boosted-lopinavir, and efavirenz pharmacokinetics.
STUDY DESIGN
We enrolled postpartum women using etonogestrel implants and receiving ritonavir-boosted-atazanavir, ritonavir-boosted-lopinavir, or efavirenz-based regimens between 2012 and 2015. Etonogestrel implants were inserted 2 to 12 weeks postpartum. We performed pharmacokinetic sampling pre-etonogestrel insertion and 6 to 7 weeks postinsertion. We measured antiretroviral concentrations pre and postetonogestrel insertion, and compared etonogestrel concentrations between antiretroviral regimens. We considered a minimum serum etonogestrel concentration of 90 pg/mL adequate for ovulation suppression.
RESULTS
We collected pharmacokinetic data for 74 postpartum women, 22 on ritonavir-boosted-atazanavir, 26 on ritonavir-boosted-lopinavir, and 26 on efavirenz. The median serum concentrations of etonogestrel when co-administered were highest with etonogestrel/ritonavir-boosted-atazanavir (604 pg/mL) and etonogestrel/ritonavir-boosted-lopinavir (428 pg/mL), and lowest with etonogestrel/efavirenz (125 pg/mL); p < 0.001. Minimum concentration (Cmin) of ritonavir-boosted-atazanavir and ritonavir-boosted-lopinavir were lower after etonogestrel implant insertion, but overall exposure, predose concentrations, clearance, and half-lives were unchanged. We found no significant change in efavirenz exposure after etonogestrel insertion.
CONCLUSIONS
Unlike efavirenz, ritonavir-boosted-atazanavir and ritonavir-boosted-lopinavir were not associated with significant decreases in etonogestrel concentrations. Efavirenz was associated with a significant decrease in etonogestrel concentrations.
IMPLICATIONS
The findings demonstrate no interactions between etonogestrel and ritonavir-boosted-lopinavir or ritonavir-boosted-atazanavir, but confirm the decreased efficacy of etonogestrel with efavirenz-based antiretrovirals. This information should be used to counsel women with HIV who desire long-acting reversible contraceptives.
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