Nevirapine + Etonogestrel = Unknown or no reaction

Effect on Concentration

Nevirapine
Unknown
Applies within class?
No
Etonogestrel
No change
Applies within class?
No

Pharmacologic Effects

Nevirapine
Effect
N/A
Applies within class?
No
Etonogestrel
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 24-Apr-2019

Summary

The use of NVP does not result in lower concentration of etonogestrel containing contraceptive implant. Therefore, it does not warrant second method of contraception.

Sources

NVP Vs. Etonorgestrel ^

Study Design

The authors included 60 HIV-positive implant users enrolled in the Partners PrEP Study in Kenya and Uganda. Blood samples were collected at 6-month intervals and antiretroviral therapy (ART) initiation was self-reported. We measured serum LNG and ENG concentrations using liquid chromatography- tandem mass spectrometry and genotyped 18 variants in CYP2B6, CYP2A6, CYP3A4, CYP3A5, NR1I2 and ABCB1. We used linear mixed models to calculate geometric mean ratios (GMRs) comparing post-ART to pre-ART progestin concentrations, and to assess for interactions between ART group and allele variants. Multivariable models adjusted for age, nationality, body mass index, closest HIV viral load, days from ART initiation, and implant type

Study Results

EFV- and nevirapine (NVP)-containing regimens were initiated by 11 and 13 women during the study, respectively; 36 women did not initiate ART and therefore contributed only pre-ART initiation data. In multivariable models, geometric mean serum LNG and ENG concentrations were 61% and 49% lower with EFV use compared to pre-ART initiation, respectively (LNG GMR=0.39, 95% CI: 0.31-0.49; ENG GMR=0.51, 95% CI: 0.34-0.76). GMRs of EFV use vs. pre-ART initiation progestin concentrations were lower with CYP3A5 rs776746 (p=0.009), CYP3A5 rs41303343 (p=0.002), CYP2B6 rs28399499 (p=0.001), and ABCB1 rs1045642 (p<0.001) allele variants relative to the wildtype (Table 1). They found no significant differences in LNG or ENG concentrations, or interactions between ART group and allele variants, with NVP use.

Study Conclusions

The authors concluded that the use of EFV but not NVP resulted in lower LNG and ENG concentrations among implant users, and polymorphisms in CYP450 enzyme (CYP3A5 and CYP2B6) and ATP-binding cassette transporter (ABCB1) genes resulted in greater decreases, suggesting a modulating role of genetics.

References

Baeten, J, Scarsi, K, Tamraz, B, Thomas, K, Erikson, D, Lingappa, J, etc.. Pharmacokinetic and pharmacogenetic assessment of art and contraceptive implants. Conference On Retroviruses And Opportunistic Infections. 2019; : .