Effect of antiretroviral therapy including lopinavir/ritonavir or efavirenz on etonogestrel-releasing implant pharmacokinetics in HIV-positive women

A randomized trial of double vs single-dose etonogestrel implant to overcome the interaction with efavirenz-based antiretroviral therapy

BACKGROUND

Concomitant use of efavirenz-based antiretroviral therapy and a standard-dose etonogestrel contraceptive implant led to 82% lower etonogestrel exposure when compared with women who do not receive antiretroviral therapy. The clinical impact of this reduced exposure is supported by retrospective cohort evaluations that demonstrated higher rates of unintended pregnancies when contraceptive implants were combined with efavirenz. We hypothesized that placement of 2 etonogestrel implants in those taking efavirenz-based antiretroviral therapy could increase etonogestrel exposure and improve measures of contraceptive efficacy.

OBJECTIVE

This study compared the rate of ovulation and etonogestrel pharmacokinetics among women on efavirenz-based antiretroviral therapy who received 2 etonogestrel implants (136 mg; double implant group) in comparison with those who received 1 etonogestrel implant (68 mg; control group).

STUDY DESIGN

This randomized, open-label study enrolled Ugandan women with regular menstrual periods who were receiving efavirenz-based antiretroviral therapy for the treatment of HIV. Participants were randomized 1:1 to the double implant or control group, and the etonogestrel implant(s) were placed in the same arm at enrollment. All participants used a copper intrauterine device to prevent pregnancy. Ovulation was evaluated by weekly serum progesterone concentrations measured over 4 consecutive weeks at months 3 (weeks 9-12), 6 (weeks 21-24), and 12 (weeks 45-48). Progesterone concentrations >3 ng/mL were interpreted as ovulation. The ovulation rate in each group was compared using Fisher's exact tests for each month and generalized estimating equations over 48 weeks. Plasma was collected at day 3 and weeks 1, 4, 12, 24, 36, and 48 after implant placement and analyzed using a validated liquid chromatography-triple quadrupole mass spectrometry method for etonogestrel. Etonogestrel concentrations were summarized as median (interquartile range) and compared between groups by geometric mean ratio with 90% confidence intervals.

RESULTS

All participants (n=72) were cisgender Ugandan women with a median age of 31 years (interquartile range, 29-36), and 36 participants were enrolled in each study group. Two participants in the control group discontinued the trial; 1 at week 1 because of undetected pregnancy at entry and another at week 45 because of clinically significant depression. There were 47 ovulations over 104 person-months (45%) in 25 of 34 participants in the control group, and 2 ovulations over 108 person-months (2%) in 2 of 36 participants in the double implant group (month 3: 11 [31%] vs 0 [0%]; month 6: 17 [49%] vs 0 [0%]; month 12: 19 [56%] vs 2 [6%], respectively; all P<.001). The odds of ovulation were reduced by 97.7% (95% confidence interval, 90.1-99.5) in the double implant group over 48 weeks. At each time point, etonogestrel concentration was more than 2-fold higher in the double implant group than in the controls (geometric mean ratio, 2.30-2.83) with a geometric mean ratio of 2.83 (90% confidence interval, 1.89-3.35) at week 48. There were no differences in the adverse events between groups and no participant discontinued because of adverse events.

CONCLUSION

Over 48 weeks of combined use, placing 2 etonogestrel implants suppressed ovulation and increased plasma etonogestrel exposure when compared with 1 etonogestrel implant among women on efavirenz-based antiretroviral therapy. Doubling the dose of etonogestrel during efavirenz-based antiretroviral therapy could improve contraceptive effectiveness.

Contraception and Abortion Care for People Living With HIV: A Clinical Guide for Reproductive Health Practitioners

People capable of pregnancy are disproportionately affected by HIV. Family planning needs and services are often unmet in this population, and clinical care guidelines regarding contraceptive options and abortion care are not well elucidated. Individuals living with HIV often face unique barriers in accessing contraception and abortion services due to internalized stigma, medically complex care (eg, drug-drug interactions, adverse effects of antiretroviral therapy), and distrust of health care providers. There is also a lack of clarity among reproductive health, primary, and infectious disease care providers on best-practice contraceptive counseling and contraceptive care for individuals living with HIV, given limited opportunities to enhance expertise in reproductive infectious disease. In this review, we summarize existing and updated evidence and clinical considerations regarding contraceptive counseling and abortion care in this population.

The effect of rifampin on serum etonogestrel concentrations and biomarkers of ovulation among contraceptive implant users: A pharmacokinetic and pharmacodynamic study

OBJECTIVES

Rifampin, a strong CYP3A inducer, is the gold standard for evaluating CYP3A-mediated drug-drug interactions. We aimed to evaluate the pharmacokinetic and pharmacodynamic effects of a short course (2 weeks) of rifampin on serum etonogestrel (ENG) concentrations and serologic measures of ovarian activity (endogenous estradiol [E2] and progesterone [P4]) among ENG implant users.

STUDY DESIGN

We enrolled healthy females using ENG implants for 12 to 36 months. We measured baseline serum ENG concentrations using a validated liquid chromatography mass-spectrometry assay and baseline E2 and P4 concentrations using chemiluminescent immunoassays. After 2 weeks of rifampin 600 mg daily, we repeated ENG, E2, and P4 measurements. We compared pre- and post-rifampin serum measurements using paired Wilcoxon signed-rank tests.

RESULTS

Fifteen participants completed all study procedures. Participants' median age was 28.2 years (range 21.8-34.1), median body-mass index was 25.2 kg/m2 (range 18.9-37.3), and median duration of implant use was 22 months (range 12-32). All participants experienced significant decreases from baseline ENG concentrations (median 164.0 pg/mL [range 94.4-265.0]) to post-rifampin measurements (median 47.8 pg/mL [range 24.7-82.8]) (p < 0.001). Serum E2 concentrations also significantly increased with rifampin exposure (median 73 pg/mL vs 202 pg/mL, p = 0.003); increases in serum P4 concentrations were not statistically significant (p = 0.19). Three participants (20%) experienced increased luteal activity, with one presumptively ovulating post-rifampin (P4 = 15.8 ng/mL).

CONCLUSIONS

With only short exposure to a strong CYP3A inducer, ENG implant users experienced clinically significant decreases in serum ENG concentrations that led to changes in biomarkers indicative of waning suppression of ovulation.

IMPLICATIONS

Even a short, 2-week course of treatment with rifampin places etonogestrel contraceptive implant users at risk for decreased contraceptive efficacy. Clinicians should counsel patients using etonogestrel implants considering any duration of rifampin therapy on the need for backup nonhormonal contraception or the use of an intrauterine device to avoid unintended pregnancies.

Prevention of the Vertical Transmission of HIV; A Recap of the Journey so Far

In 1989, one in four (25%) infants born to women living with HIV were infected; by the age of 2 years, there was 25% mortality among them due to HIV. These and other pieces of data prompted the development of interventions to offset vertical transmission, including the landmark Pediatric AIDS Clinical Trial Group Study (PACTG 076) in 1994. This study reported a 67.5% reduction in perinatal HIV transmission with prophylactic antenatal, intrapartum, and postnatal zidovudine. Numerous studies since then have provided compelling evidence to further optimize interventions, such that annual transmission rates of 0% are now reported by many health departments in the US and elimination has been validated in several countries around the world. Despite this success, the elimination of HIV’s vertical transmission on the global scale remains a work in progress, limited by socioeconomic factors such as the prohibitive cost of antiretrovirals. Here, we review some of the key trials underpinning the development of guidelines in the US as well as globally, and discuss the evidence through a historic lens.

Effect of double-dose levonorgestrel subdermal implant in women taking efavirenz-based antiretroviral therapy: The DoubLNG pharmacokinetic study

OBJECTIVE

We evaluated the pharmacokinetics of double-dose levonorgestrel (LNG) implants to overcome the drug-drug interaction with efavirenz-based antiretroviral therapy (ART).

STUDY DESIGN

We conducted a nonrandomized, open-label, parallel-group, longitudinal pharmacokinetic study among Ugandan women ages 18-45 years. Participants with HIV on ART containing efavirenz 600 mg received 300 mg of LNG implants (Jadelle®, Bayer, New Zealand): 300LNG+ART group. We compared our outcomes with women without HIV using standard dose, 150 mg of LNG implants: 150LNG group. The implant was placed on day zero in both groups, and we quantified plasma LNG concentrations over 48 weeks post implant insertion. LNG pharmacokinetic parameters were estimated using noncompartmental techniques. Our primary outcome was the geometric mean ratio with 90% confidence intervals of LNG area under the concentration-time curve over 24 weeks (AUC_0-24w) between groups. Demographic data were described as median (interquartile range). A secondary outcome compared between-group percent of LNG concentrations ≥300 pg/mL, a minimum threshold selected a priori based on observed pregnancies in Ugandan women on standard-dose LNG implants plus efavirenz.

RESULTS

We enrolled 27 women in the 300LNG+ART group (34 [28.0 to 40.5] years and 61.0 [49.8-66.0] kg) and 19 women in the 150LNG group (33 [30.0 to 34.5] years and 64.9 [59.0 to 74.5] kg). LNG AUC_0-24w was 34% lower for 300LNG+ART versus 150LNG (geometric mean 9998 vs. 15,231 pg*week/mL, respectively [geometric mean ratio 0.66 (90% confidence intervals, 0.54 to 0.80)]). The percentage of participants with LNG concentrations ≥300 pg/mL was not statistically different between groups at week 24 (300LNG+ART: 74.1%; 150LNG: 89.5%; p = 0.27).

CONCLUSION

Double-dose LNG implant did not completely overcome the drug-drug interaction with efavirenz.

IMPLICATION

In women using ART containing efavirenz, placing two implant systems (300 mg) did not normalize LNG pharmacokinetics compared with the standard-dose implant (150 mg), and some women had evidence of ovulatory activity. Alternative ART without drug-drug interactions, such as dolutegravir, is recommended with contraceptive implants.

Pharmacokinetics of levonorgestrel and etonogestrel contraceptive implants over 48 weeks with rilpivirine- or darunavir-based antiretroviral therapy

BACKGROUND

Pharmacokinetic data are lacking for progestin-releasing subdermal contraceptive implants when used with either rilpivirine- or darunavir/ritonavir-based ART.

OBJECTIVES

To characterize the pharmacokinetics of etonogestrel or levonorgestrel implants when administered with these ART regimens over 48 weeks.

PATIENTS AND METHODS

Two separate, parallel, three-group, non-randomized, pharmacokinetic studies evaluated either etonogestrel or levonorgestrel in women receiving rilpivirine- or darunavir-based ART compared with women without HIV (control group). Participants on ART were switched to rilpivirine-based ART with a run-in period of 6 weeks or darunavir-based ART with a run-in of 2 weeks prior to implant insertion. Plasma was collected on Day 0, and 1, 4, 12, 24, 36 and 48 weeks post-insertion. Plasma progestin concentrations were compared between ART and control groups by geometric mean ratio (GMR) and 90% CI.

RESULTS

At the primary endpoint of Week 24, progestin concentrations were similar between the rilpivirine and control groups [etonogestrel: 1.18 (0.99-1.37); levonorgestrel: 1.16 (0.97-1.33)]. At Week 24, progestin exposure was higher in the darunavir groups compared with the control group [etonogestrel: 2.56 (1.69-3.28); levonorgestrel: 1.89 (1.38-2.29)]. Results remained consistent through to Week 48. No differences in etonogestrel-related adverse events were observed, but both ART groups experienced more menstrual abnormalities versus the control group with levonorgestrel.

CONCLUSIONS

Etonogestrel and levonorgestrel concentrations were not altered by rilpivirine-based ART. Although progestin concentrations were higher in the ART groups containing ritonavir-boosted darunavir, no implant-related serious adverse events were observed. Both progestin-releasing implants are an appropriate contraceptive option with either rilpivirine- or darunavir/ritonavir-based ART.

Society of Family Planning Clinical Recommendations: Contraceptive Care in the Context of Pandemic Response

The coronavirus disease 2019 (COVID-19) pandemic has posed a burden to healthcare systems around the world and has changed the way people access health services, including contraception. This document sets forth guidance from the Society of Family Planning for providing contraceptive care in the context of the COVID-19 pandemic, including when access to healthcare is restricted due to pandemic response. It also outlines the role of telehealth for providing contraceptive care beyond the pandemic. Clinicians can use synchronous telemedicine visits and other forms of telehealth to provide many aspects of contraceptive care. Both audio-video and audio-only visits are acceptable forms of telemedicine. Access to permanent contraception should be maintained, especially in the postpartum period. Combined hormonal contraceptive (CHC) users who have asymptomatic or mild COVID-19 infection may continue their contraceptive method, while those admitted to the hospital with severe infection should suspend CHC use until they are clinically recovered. CHC users who take Paxlovid for mild-moderate COVID-19 infection can consider a back-up contraceptive method for the duration of therapy, but clinically relevant drug interactions are unlikely. Future research should examine contraceptive outcomes in people who receive care via telemedicine; and access to telemedicine among historically excluded populations such as adolescents, people of color, people of low socioeconomic status, disabled people, or people who do not speak English as a primary language.

Contraceptive implant use duration is not associated with breakthrough pregnancy among women living with HIV and using efavirenz: a retrospective, longitudinal analysis

Introduction

Contraceptive implants containing etonogestrel and levonorgestrel have emerged as popular contraceptive options among women in areas of high HIV burden in sub‐Saharan Africa. However, recent pharmacokinetic data have shown drug–drug interactions between implants and efavirenz‐containing antiretroviral therapy (ART), reducing the effectiveness of the implants. Here, we evaluated pregnancy incidence in 6‐month intervals following implant initiation among women using efavirenz and contraceptive implants to assess whether the risk of breakthrough pregnancy is higher after specific periods of implant use.

Methods

We used data from a retrospective longitudinal analysis of women living with HIV ages 18–45 years in western Kenya who attended HIV‐care facilities between 2011 and 2015. We used Cox proportional hazard models to compute hazard ratios (HRs) for breakthrough pregnancy by implant type and ART regimen. Depending on the model, we adjusted for socio‐demographic and clinical factors, programme, site and interaction between calendar time and ART regimen. We utilized inverse probability weights (IPWs) to account for three sampling phases (electronic medical record [EMR], chart review and phone interview) and calculated overall parameter estimates.

Results

Women contributed 14,768 woman‐years from the largest sampling phase (EMR). The median age was 31 years. Women used etonogestrel implants for 26–69% of the time and levonorgestrel implants for 7–31% of the time, depending on the sampling phase. Women used efavirenz, nevirapine or no ART for 27–33%, 40–46% and 15–26% of follow‐ups, respectively. When combining sampling phases, there was little evidence to suggest that the relative hazard of pregnancy among efavirenz‐containing ART users relative to nevirapine‐containing ART changed with length of time on implants: IPW‐adjusted HR of 3.1 (CI: [1.5; 6.4]) at 12 months, 3.4 (CI: [1.8; 6.3]) at 24 months, 3.8 (CI: [1.9; 7.7]) at 36 months and 4.2 (CI: [1.6; 11.1]) at 48 months (interaction p‐value = 0.88). Similarly, no significant change in HRs over time was found when comparing women not using ART to nevirapine‐containing ART users (interaction p‐value = 0.49).

Conclusions

We did not find evidence to suggest implants being more fallible from drug–drug interactions with efavirenz at later time intervals of implant use. Thus, we would not recommend shortening the duration of implant use or replacing implants sooner when concomitantly used with efavirenz.

Interactions between etonogestrel-releasing contraceptive implant and 3 antiretroviral regimens

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 (C_min) 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.

Pregnancies among women living with HIV using contraceptives and antiretroviral therapy in western Kenya: a retrospective, cohort study

BACKGROUND

Preventing unintended pregnancies is paramount for women living with HIV (WLHIV). Previous studies have suggested that efavirenz-containing antiretroviral therapy (ART) reduces contraceptive effectiveness of implants, but there are uncertainties regarding the quality of the electronic medical record (EMR) data used in these prior studies.

METHODS

We conducted a retrospective, cohort study of EMR data from 2011 to 2015 among WLHIV of reproductive age accessing HIV care in public facilities in western Kenya. We validated a large subsample of records with manual chart review and telephone interviews. We estimated adjusted incidence rate ratios (aIRRs) with Poisson regression accounting for the validation sampling using inverse probability weighting and generalized raking.

RESULTS

A total of 85,324 women contributed a total of 170,845 women-years (w-y) of observation time; a subset of 5080 women had their charts reviewed, and 1285 underwent interviews. Among implant users, the aIRR of pregnancy for efavirenz- vs. nevirapine-containing ART was 1.9 (95% CI 1.6, 2.4) using EMR data only and 3.2 (95% CI 1.8, 5.7) when additionally using both chart review and interview validated data. Among efavirenz users, the aIRR of pregnancy for depomedroxyprogesterone acetate (DMPA) vs. implant use was 1.8 (95% CI 1.5, 2.1) in EMR only and 2.4 (95% CI 1.0, 6.1) using validated data.

CONCLUSION

Pregnancy rates are higher when contraceptive implants are concomitantly used with efavirenz-containing ART, though rates were similar to leading alternative contraceptive methods such as DMPA. Our data provides policymakers, program staff, and WLHIV greater confidence in guiding their decision-making around contraceptive and ART options. Our novel, 3-phase validation sampling provides an innovative tool for using routine EMR data to improve the robustness of data quality.

Multipurpose Prevention Technologies: Oral, Parenteral, and Vaginal Dosage Forms for Prevention of HIV/STIs and Unplanned Pregnancy

There is a high global prevalence of HIV, sexually transmitted infections (STIs), and unplanned pregnancies. Current preventative daily oral dosing regimens can be ineffective due to low patient adherence. Sustained release delivery systems in conjunction with multipurpose prevention technologies (MPTs) can reduce high rates of HIV/STIs and unplanned pregnancies in an all-in-one efficacious, acceptable, and easily accessible technology to allow for prolonged release of antivirals and contraceptives. The concept and development of MPTs have greatly progressed over the past decade and demonstrate efficacious technologies that are user-accepted with potentially high adherence. This review gives a comprehensive overview of the latest oral, parenteral, and vaginally delivered MPTs in development as well as drug delivery formulations with the potential to advance as an MPT, and implementation studies regarding MPT user acceptability and adherence. Furthermore, there is a focus on MPT intravaginal rings emphasizing injection molding and hot-melt extrusion manufacturing limitations and emerging fabrication advancements. Lastly, formulation development considerations and limitations are discussed, such as nonhormonal contraceptive considerations, challenges with achieving a stable coformulation of multiple drugs, achieving sustained and controlled drug release, limiting drug-drug interactions, and advancing past preclinical development stages. Despite the challenges in the MPT landscape, these technologies demonstrate the potential to bridge gaps in preventative sexual and reproductive health care.

Pharmacogenetic interactions between antiretroviral drugs and vaginally administered hormonal contraceptives

OBJECTIVE

In AIDS Clinical Trials Group study A5316, efavirenz lowered plasma concentrations of etonogestrel and ethinyl estradiol, given as a vaginal ring, while atazanavir/ritonavir increased etonogestrel and lowered ethinyl estradiol concentrations. We characterized the pharmacogenetics of these interactions.

METHODS

In A5316, women with HIV enrolled into control (no antiretrovirals), efavirenz [600 mg daily with nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)], and atazanavir/ritonavir (300/100 mg daily with NRTIs) groups. On day 0, a vaginal ring was inserted, releasing etonogestrel/ethinyl estradiol 120/15 μg/day. Intensive plasma sampling for antiretrovirals was obtained on days 0 and 21, and single samples for etonogestrel and ethinyl estradiol on days 7, 14, and 21. Seventeen genetic polymorphisms were analyzed.

RESULTS

The 72 participants in this analysis included 25, 24 and 23 in the control, efavirenz, and atazanavir/ritonavir groups, respectively. At day 21 in the efavirenz group, CYP2B6 genotype was associated with increased plasma efavirenz exposure (P = 3.2 × 10), decreased plasma concentrations of etonogestrel (P = 1.7 × 10), and decreased ethinyl estradiol (P = 6.7 × 10). Compared to controls, efavirenz reduced median etonogestrel concentrations by at least 93% in CYP2B6 slow metabolizers versus approximately 75% in normal and intermediate metabolizers. Efavirenz reduced median ethinyl estradiol concentrations by 75% in CYP2B6 slow metabolizers versus approximately 41% in normal and intermediate metabolizers.

CONCLUSION

CYP2B6 slow metabolizer genotype worsens the pharmacokinetic interaction of efavirenz with hormonal contraceptives administered by vaginal ring. Efavirenz dose reduction in CYP2B6 slow metabolizers may reduce, but will likely not eliminate, this interaction.

Comparison of plasma etonogestrel concentrations sampled from the contralateral-to-implant and ipsilateral-to-implant arms of contraceptive implant users

OBJECTIVE

To compare plasma etonogestrel concentrations sampled from the contralateral- versus ipsilateral-to-implant arm.

STUDY DESIGN

Sub-analysis of a cross-sectional study in Botswana in 33 participants who provided contralateral and ipsilateral blood samples.

RESULTS

Plasma etonogestrel concentrations in contralateral and ipsilateral specimens were highly correlated (correlation coefficient = 0.99; p < 0.0001). Bland-Altman analysis of agreement showed that etonogestrel levels were on average 5.9 pg/mL higher (2.1%) in ipsilateral compared to contralateral specimens (95% confidence interval: -4.1, 15.9 pg/mL).

CONCLUSIONS

We found no meaningful differences in plasma etonogestrel concentrations between samples taken from the contralateral- versus ipsilateral-to-implant arm.

IMPLICATIONS

Our data suggest that etonogestrel plasma concentrations are unlikely to be meaningfully different between samples drawn from the ipsilateral- versus the contralateral-to-implant arms in etonogestrel contraceptive implant users.

Effect of patient genetics on etonogestrel pharmacokinetics when combined with efavirenz or nevirapine ART

BACKGROUND

We previously demonstrated that etonogestrel concentrations were 82% lower in women using etonogestrel contraceptive implants plus efavirenz-based ART compared with women not receiving ART.

OBJECTIVES

To investigate the genetic contribution to this previously observed drug-drug interaction through studying SNPs in genes known to be involved in efavirenz, nevirapine or etonogestrel metabolism in the same group of women.

PATIENTS AND METHODS

Here, we present a secondary analysis evaluating SNPs involved in efavirenz, nevirapine and etonogestrel metabolism and associated etonogestrel pharmacokinetics among 57 women, 19 not receiving ART (control group), 19 receiving efavirenz- (600 mg daily) based ART and 19 receiving nevirapine- (200 mg twice daily) based ART. Associations between patient genotype and etonogestrel pharmacokinetic parameters were determined through univariate and multivariate linear regression. This study was registered at clinicaltrials.gov (NCT02082652).

RESULTS

Within the control group, CYP2B6 983 T>C was associated with 27% higher etonogestrel Cmax and 28% higher AUC0-24weeks. In the efavirenz group CYP2B6 516 G>T was associated with 43% lower etonogestrel Cmin and 34% lower AUC0-24weeks. For participants receiving nevirapine, NR1I2 63396 C>T was associated with 39% lower etonogestrel Cmin and 37% lower AUC0-24weeks.

CONCLUSIONS

This study demonstrates the influence of pharmacogenetics on the extent of drug-drug interactions between etonogestrel and efavirenz- or nevirapine-based ART. Efavirenz plus the etonogestrel contraceptive implant results in a detrimental drug-drug interaction irrespective of patient genetics, which is worsened in women possessing variant alleles for these CYP2B6 SNPs.

Potential risk of drug-drug interactions with hormonal contraceptives and antiretrovirals: prevalence in women living with HIV

Background

Family planning services are vital for women living with HIV (WLH); however, the use of concomitant antiretroviral therapy (ART) and hormonal contraceptives (HCs) may pose challenges due to the risk of potential drug–drug interactions (DDIs). The objectives of this study were to assess ART and HC use among WLH and quantify the frequency of potential DDIs between ART and HCs.

Methods

This was a retrospective, observational, cohort study of WLH aged 18–55 years, prescribed ART, with at least one clinic visit from January 1, 2010 to April 30, 2014. Potential DDIs between HCs and ART were assessed using the University of Liverpool HIV Drug Interactions website (www.hiv-druginteractions.org) and categorized as ‘weak potential interaction,’ ‘potential interaction,’ or ‘do not co-administer.’

Results

Overall, a contraceptive method was reported in 167 (54%) of the 309 women included in the study. Of those using contraception, 73 (43.7%) reported using HCs, which was most frequently a progestin intrauterine device (n=43), progestin injection (n=17), or combination oral contraceptive pills (n=9). Out of a total of 449 ART regimens, a potential DDI was identified in 21 of 115 (18.3%) ART–HC combinations from 19 women using ART and HCs. Atazanavir/ritonavir was the most common potentially interacting ART (10, 47.6%); for HCs, these were combination oral contraceptive pills (16, 76.2%) and progestin implants (2, 9.5%).

Conclusion

In this cohort, one-quarter of WLH on ART–HCs had a potential DDI. Future studies should investigate the impact of DDIs on unintended pregnancies, the side effects of DDIs, and the effects of HC DDIs on ART concentrations.

Contraceptive implant failures among women using antiretroviral therapy in western Kenya: a retrospective cohort study

Background: Women living with HIV have the right to choose whether, when and how many children to have. Access to antiretroviral therapy (ART) and contraceptives, including implants, continues to increase in Kenya. Studies have reported drug-drug interactions leading to contraceptive failures among implant users on ART. This retrospective record review aimed to determine unintentional pregnancy rates among women 15-49 years of age, living with HIV and concurrently using implants and ART in western Kenya between 2011 and 2015.

Methods: We reviewed charts of women with more than three months of concurrent implant and ART use. Implant failure was defined as implant removal due to pregnancy or birth after implant placement, but prior to scheduled removal date. The incidence of contraceptive failure was calculated by woman-years at risk, assuming a constant rate.

Results: Data from 1,152 charts were abstracted, resulting in 1,190 implant and ART combinations. We identified 115 pregnancies, yielding a pregnancy incidence rate of 6.32 (5.27–7.59), with 9.26 among ETG and 4.74 among LNG implant users, respectively. Pregnancy incidence rates did not differ between EFV- and NVP-based regimens (IRR=1.00, CI: 0.71-1.43). No pregnancies were recorded among women on PI-based regimens, whereas pregnancy rates for efavirenz and nevirapine-containing regimens were similar, at 6.41 (4.70–8.73) and 6.44 (5.13–8.07), respectively. Pregnancy rates also differed significantly by implant type, with LNG implant users half as likely to experience pregnancy as ETG implant users (0.51, CI: 0.33-0.79, p>0.01).

Conclusions: Our findings highlight the implications of drug-drug interaction on women’s choices for contraception.

A pharmacokinetic and pharmacogenetic evaluation of contraceptive implants and antiretroviral therapy among women in Kenya and Uganda

OBJECTIVES

To evaluate pharmacokinetics and pharmacogenetics of contraceptive implant progestin concentrations in HIV-positive women initiating efavirenz (EFV)-containing or nevirapine (NVP)-containing antiretroviral therapy (ART).

DESIGN

We analyzed stored samples from women self-reporting implant use in the Partners PrEP Study.

METHODS

Plasma samples collected every 6 months were analyzed for levonorgestrel and etonogestrel concentrations. Progestin concentrations from samples collected after ART initiation were compared with pre-ART concentrations for intraindividual comparisons. We used adjusted linear mixed models to compare hormone concentrations between individuals on EFV and NVP to a no ART group. We then evaluated whether possessing certain alleles with known or possible influences on EFV, NVP, or progestin metabolism were associated with changes in progestin concentrations or modified the association between ART use and progestin concentrations.

RESULTS

Our analysis included 11 women who initiated EFV, 13 who initiated NVP, and 36 who remained ART-naive. In the EFV group, the adjusted geometric mean ratio (aGMR) of levonorgestrel was 0.39 [90% confidence intervals (0.31, 0.49); P < 0.001] and the etonogestrel aGMR was 0.51 (0.34, 0.76; P = 0.006) compared with the control group. No difference was observed in the NVP group compared with controls [levonorgestrel 0.93 (0.74, 1.18); P = 0.64; etonogestrel 1.07 (0.77, 1.50); P = 0.73]. Possession of four allele variants were found to result in further reductions in progestin concentrations among those receiving EFV.

CONCLUSION

Concomitant use of EFV significantly reduces levonorgestrel or etonogestrel concentrations by 61 and 49%, respectively, compared with no ART use. We also report allelic variants in hepatic enzymes that influenced the extent of the observed drug-interaction between progestins and EFV.

Antiretroviral therapy and vaginally administered contraceptive hormones: a three-arm, pharmacokinetic study

BACKGROUND

Drug-drug interactions between orally administered antiretroviral therapy (ART) and hormones released from an intravaginal ring are not known. We hypothesised that ART containing either efavirenz or ritonavir-boosted atazanavir would alter plasma concentrations of vaginally administered etonogestrel and ethinylestradiol but that ART concentrations would be unchanged during use of an intravaginal ring.

METHODS

We did a parallel, three-group, pharmacokinetic evaluation at HIV clinics in Asia (two sites), South America (five), sub-Saharan Africa (three), and the USA (11) between Dec 30, 2014, and Sept 12, 2016. We enrolled women with HIV who were either ART-naive (control group; n=25), receiving efavirenz-based ART (n=25), or receiving atazanavir-ritonavir-based ART (n=24). Women receiving ART were required to be on the same regimen for at least 30 days, with 400 copies or less per mL of plasma HIV-1 RNA; women not receiving ART had CD4 counts of 350 cells per μL or less. We excluded participants who had a bilateral oophorectomy or conditions that were contraindicated in the intravaginal ring product labelling. An intravaginal ring releasing etonogestrel and ethinylestradiol was inserted at entry (day 0). Single plasma samples for hormone concentrations were collected on days 7, 14, and 21 after intravaginal ring insertion. The primary outcome was the plasma concentration of etonogestrel and ethinylestradiol on day 21. Etonogestrel and ethinylestradiol concentrations were compared between each ART group and the control group by geometric mean ratio (GMR) with 90% CIs and Wilcoxon rank-sum test. As secondary outcomes, efavirenz or ritonavir-boosted atazanavir concentrations were assessed by 8-h intensive pharmacokinetic sampling at entry before intravaginal ring insertion and before intravaginal ring removal on day 21. Antiretroviral areas under the concentration-time curve (AUC0-8 h) were compared before and after intravaginal ring insertion by GMR (90% CI) and Wilcoxon signed-rank test. This study is registered with ClinicalTrials.gov, number NCT01903031.

FINDINGS

Between Dec 30, 2014, and Sept 12, 2016, we enrolled 84 participants in the study; ten participants were excluded from the primary hormone analysis. 74 participants met the primary endpoint: 25 in the control group, 25 in the efavirenz group, and 24 in the atazanavir group. On day 21 of intravaginal ring use, participants receiving efavirenz had 79% lower etonogestrel (GMR 0·21, 90% CI 0·16-0·28; p<0·0001) and 59% lower ethinylestradiol (0·41, 0·32-0·52; p<0·0001) concentrations compared with the control group. By contrast, participants receiving ritonavir-boosted atazanavir had 71% higher etonogestrel (1·71, 1·37-2·14; p<0·0001), yet 38% lower ethinylestradiol (0·62, 0·49-0·79; p=0·0037) compared with the control group. The AUC0-8 h of efavirenz or atazanavir did not differ between the groups.

INTERPRETATION

Hormone exposure was significantly lower when an intravaginal ring contraceptive was combined with efavirenz-based ART. Further studies designed to examine pharmacodynamic endpoints, such as ovulation, when intravaginal ring hormones are combined with efavirenz are warranted.

FUNDING

National Institutes of Health, through the AIDS Clinical Trials Group and the International Maternal Pediatric Adolescent AIDS Clinical Trials Network, National Institute of Allergy and Infectious Diseases, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Institute of Mental Health.

Perspectives on contraceptive implant use in women living with HIV in Cape Town, South Africa: a qualitative study among primary healthcare providers and stakeholders

BACKGROUND

This study explored primary healthcare provider and HIV/contraception expert stakeholder perspectives on South Africa's public sector provision of contraceptive implants to women living with HIV. We investigated the contraceptive service-impact of official advice against provision of implants to women using the HIV antiretroviral drug, efavirenz, issued by the South African National Department of Health (NDoH) in 2014.

METHODS

Qualitative data was collected in Cape Town in 2017 from primary healthcare contraceptive providers in four clinics that provide implants, as well as from other expert stakeholders selected for expertise in HIV and/or contraception. In-depth interviews and a group discussion explored South Africa's implant introduction and implant provision to women living with HIV. Data was analysed using an inductive thematic analysis approach.

RESULTS

Interviews were conducted with 10 providers and 10 stakeholders. None of the four clinics where the providers worked currently offered the implant to women living with HIV. Stakeholders confirmed that this was consistent with patterns of implant provision at primary healthcare facilities across Cape Town. Factors contributing to providers' decisions to suspend provision of the implant to women living with HIV included: inadequate initial and ongoing provider training; interpretation of NDoH communications about implant use with efavirenz; provider unwillingness to risk harming clients and concerns about professional liability; and other pressures related to provider capacity.

CONCLUSIONS

All South African women, including those living with HIV, should have access to the full range of contraceptive options for which they are medically eligible. Changing guidance should be initiated and communicated in consultation with primary-level providers and service beneficiaries. Guidance issued to providers needs to be clear and fully evidence-informed, and its correct interpretation and implementation facilitated and monitored. Guidance should be accompanied by provider training, as well as counselling messages and tools to support providers. Generalized retraining of providers in rights-based, client-centred family planning, and in particular implant provision for women with HIV, is needed. These recommendations accord with the right of women living with HIV to access the highest possible standard of sexual and reproductive healthcare, including informed contraceptive choice and access to the contraceptive implant.

Increasing body mass index or weight does not appear to influence the association between efavirenz-based antiretroviral therapy and implant effectiveness among HIV-positive women in western Kenya

OBJECTIVE

Our objective was to evaluate if increasing body mass index (BMI) or weight influences the association between efavirenz-based antiretroviral therapy (ART) and implant effectiveness.

STUDY DESIGN

We conducted a secondary cohort analysis of HIV-positive women aged 15 to 45 years enrolled in HIV care in western Kenya using an implant from January 2011 to December 2015. Implant use, ART regimen and weight were documented at each clinic visit and height at enrollment. We categorized BMI as underweight, normal weight, overweight or obese, and weight as <70 kg or ≥70 kg. Our primary outcome was incident pregnancy diagnosed clinically. We used crude and adjusted Poisson models with robust standard errors to account for covariates and repeated observations to estimate adjusted incident rate ratios (aIRRs).

RESULTS

In this analysis, 12,960 women contributed a total of 11,285 woman-years of observation time while using an implant, with a median of 6.6 months. The aIRRs comparing efavirenz- to nevirapine-based ART groups did not increase as BMI increased; the aIRRs were 2.0 (1.1-3.6) for underweight, 1.9 (1.5-2.5) for normal, 3.1 (1.6-6.0) for overweight and 2.1 (0.6-6.9) for obese women. The aIRRs comparing efavirenz- to nevirapine-based ART groups did not increase as weight increased; the aIRRs were 2.0 (1.6-2.6) for weight <70 kg and 2.1 (1.0-4.5) for weight ≥70 kg.

CONCLUSION

Higher BMI or weight did not appear to modify the relationship between efavirenz use and implant effectiveness.

IMPLICATIONS

Programs should not recommend differential counseling for women with higher BMI or weight who concomitantly use implants and efavirenz.

Contraceptive implant failures among women using antiretroviral therapy in western Kenya: a retrospective cohort study

Background: Women living with HIV have the right to choose whether, when and how many children to have. Access to antiretroviral therapy (ART) and contraceptives, including implants, continues to increase due to a multitude of efforts. In Kenya, 4.8% of adults are living with HIV, and in 2017, 54% were receiving an efavirenz-based ART regimen. Meanwhile, 16.1% of all Kenyan married (and 10.4% of unmarried) women used implants. Studies have reported drug interactions leading to contraceptive failures among implant users on ART. This retrospective record review aimed to determine unintentional pregnancy rates among women 15-49 years of age, living with HIV and concurrently using implants and ART in western Kenya between 2011 and 2015. Methods: We reviewed charts of women with more than three months of concurrent implant and ART use. Implant failure was defined as implant removal due to pregnancy or birth after implant placement, but prior to scheduled removal date. The incidence of unintended pregnancy was calculated by woman-years at risk, assuming a constant rate. Results: Data from 1,152 charts were abstracted, resulting in 1,190 implant and ART combinations. We identified 115 pregnancies, yielding a pregnancy incidence rate of 6.32 (5.27–7.59), with 9.26 among ETG and 4.74 among LNG implant users, respectively. No pregnancies were recorded among women on non-NNRTI-based regimens, whereas pregnancy rates for efavirenz and nevirapine-containing regimens were similar, at 6.41 (4.70–8.73) and 6.44 (5.13–8.07), respectively. Conclusions: Our findings highlight the implications of drug interaction on women’s choices for contraception.

Physiologically based pharmacokinetic modelling prediction of the effects of dose adjustment in drug-drug interactions between levonorgestrel contraceptive implants and efavirenz-based ART

Background

HIV-positive women receiving efavirenz-based ART and levonorgestrel contraceptive implants are at risk of low levonorgestrel exposure and unintended pregnancy.

Objectives

To investigate clinically applicable dose-adjustment strategies to overcome the known drug-drug interaction (DDI) between levonorgestrel and efavirenz, using a physiologically based pharmacokinetic (PBPK) modelling-based approach.

Methods

A PBPK model was qualified against clinical data to predict levonorgestrel plasma concentrations when standard-dose (150 mg) levonorgestrel implants were administered alone (control group), as well as when standard-dose or increased-dose (300 mg) levonorgestrel implants were coadministered with either 600 or 400 mg of efavirenz.

Results

No difference was seen between in vivo clinical and PBPK-model-simulated levonorgestrel plasma concentrations (P > 0.05). Simulated levonorgestrel plasma concentrations were ∼50% lower at 48 weeks post-implant-placement in virtual individuals receiving standard-dose levonorgestrel with either 600 or 400 mg of efavirenz compared with the control group (efavirenz:control geometric mean ratio = 0.42 and 0.49, respectively). Conversely, increased-dose levonorgestrel in combination with either 600 or 400 mg of efavirenz was sufficient to restore levonorgestrel concentrations to levels similar to those observed in the 150 mg levonorgestrel control group 48 weeks post-implant-placement (efavirenz:control geometric mean ratio = 0.86 and 1.03, respectively).

Conclusions

These results suggest that the clinically significant DDI between efavirenz and levonorgestrel is likely to persist despite efavirenz dose reduction, whereas dose escalation of implantable levonorgestrel may represent a successful clinical strategy to circumvent efavirenz-levonorgestrel DDIs and will be of use to inform clinical trial design to assess coadministration of efavirenz and levonorgestrel implants.

Antiretroviral implants for treatment and prevention of HIV infection

PURPOSE OF REVIEW

Poor adherence to oral antiretroviral formulations remains the major barrier to the success of long-term treatment and prevention strategies. Although a number of approaches have been developed for long-acting parenteral delivery of antiretroviral drugs, subcutaneous implants are a particularly promising technology as they may be able to provide protective drugs concentrations for a year or longer following a single implant. This review addresses the current status of preclinical and clinical development of antiretroviral implants.

RECENT FINDINGS

Subcutaneous implants have been widely used for hormonal contraception and the treatment of hormonally driven malignancies for more than 3 decades. These implants are economical to manufacture and deliver, but require special procedures for insertion and removal. They are generally well tolerated and can remain in place for as long as 5 years. A small number of investigational implants are under development for the delivery of antiretroviral drugs. The most advanced of these, containing the investigational antiretroviral MK-8591 (4'-ethynyl-2-fluoro-2'-deoxyadenosine), a potent nucleoside analog reverse transcriptase translocation inhibitor that demonstrates particular promise for subcutaneous implantation, is closest to testing in human subjects. Investigational implants containing tenofovir alafenamide and nevirapine have also been developed and tested in animal models.

SUMMARY

Long-acting antiretroviral implants are a promising new technology, but are in very early stages of development. Potential advantages of these systems include more consistent and predictable drug release than intramuscular injections, and the fact that implants can be removed in the case of adverse events or the desire to stop treatment.

HIV and contraception

PURPOSE OF REVIEW

Contraception is a vital component of medical care for women with HIV or at high risk of acquiring HIV. Over the last several years, there has been emerging evidence regarding the safety and effectiveness of various contraceptive methods, ultimately leading to a revision in the WHO Medical Eligibility Criteria for contraceptive use.

RECENT FINDINGS

Progestogen-only injectables may be associated with an increased risk of HIV acquisition and its use has been revised to category 2 from category 1. Etonogestrel and levonorgestrel levels are lower in women who concurrently use contraceptive implant and efavirenz-based antiretroviral therapy. Multipurpose technology, aimed at providing antiretroviral medication and contraception, is an area of ongoing research but is not yet clinically available.

SUMMARY

It is important for providers who care for women with HIV or at high risk of HIV to inquire about pregnancy intentions. If contraception is desired, these women should be offered all available methods, with counseling regarding possible risks of contraceptive failure or HIV acquisition.

Development, validation and utilization of a highly sensitive LC-MS/MS method for quantification of levonorgestrel released from a subdermal implant in human plasma

Levonorgestrel (LNG) is a synthetic progestin that is available in oral contraceptive tablets, a subdermal implant, and an intrauterine system for contraception. LNG pharmacokinetics are a pivotal determinant of contraceptive efficacy and essential in assessing drug-drug interactions influencing LNG exposure following different routes of LNG administration. A highly sensitive LC-MS/MS method was developed and validated to quantify levonorgestrel in human plasma. Liquid-liquid extraction was utilized with a sample volume of 500 μL to extract levonorgestrel from plasma. Chromatographic separation of LNG was achieved with a Fortis™ C18 (3 μm: 100 mm × 2.1 mm) reverse phase analytical column. The mobile phases consisted of de-ionized water plus 0.1% NH4OH (100:0.1%, v/v) (A), and methanol plus 0.1% NH4OH (100:0.1%, v/v) (B) delivered as a gradient at a flow rate of 400 μL/min. Detection of LNG and internal standard (D-(-)-norgestrel-d7) was achieved using positive polarity mode monitoring at 313.2-245.2 amu and 320.1-251.2 amu, respectively. The assay was linear over the calibration range of 49.6 to 1500 pg/mL. This method was used to quantify plasma LNG released by subdermal implant in support of a drug interaction study among women with HIV receiving efavirenz- or nevirapine-based antiretroviral therapy.

Simultaneous quantitation of multiple contraceptive hormones in human serum by LC-MS/MS

OBJECTIVE

The objective was to develop a method to simultaneously quantify five commonly used hormonal contraceptives (HCs) and two endogenous sex steroids by liquid chromatography-tandem triple quadrupole mass spectrometry (LC-MS/MS) and apply this method to human serum samples.

STUDY DESIGN

We developed a method to simultaneously analyze ethinyl estradiol (EE2), etonogestrel (ENG), levonorgestrel (LNG), medroxyprogesterone acetate (MPA) and norethisterone (NET), along with estradiol (E2) and progesterone (P4), in human serum for a Shimadzu Nexera-LCMS-8050 LC-MS/MS platform. We analyzed serum collected from women self-reporting use of oral contraceptives, contraceptive implants or injectable contraceptives (n=14) and normally cycling women using no HC (n=15) as well as pooled samples from women administered various HCs (ENG, n=6; LNG, n=14; MPA, n=7; NET, n=5).

RESULTS

Limits of quantitation were 0.010ng/mL for E2, EE2 and P4; 0.020ng/mL for ENG, LNG and MPA; and 0.040ng/mL for NET. Precisions for all assays, as indicated by coefficient of variation, were less than or equal to 12.1%. Accuracies for all assays were in the range of 95%-108%. Endogenous hormone values obtained from analysis of human serum samples are in agreement with levels previously reported in the literature for normally cycling women as well as for women taking the appropriate HC.

CONCLUSIONS

We have developed a robust, accurate and sensitive method for simultaneously analyzing commonly used contraceptive steroids and endogenous sex steroids in human serum.

IMPLICATIONS

This analytical method can be used for quantitating contraceptive steroid levels in women for monitoring systemic exposure to determine drug interactions, nonadherence, misreporting and proper dosing.

A systematic review of contraceptive continuation among women living with HIV

BACKGROUND

Women living with HIV (WLHIV) experience high rates of unmet contraceptive need and unintended pregnancy. Contraceptive method-specific continuation rates and associated factors are critical for guiding providers tasked with both reproductive health (RH) and HIV care. We conducted this systematic review to determine whether contraceptive continuation rates differ between WLHIV and uninfected women and, for WLHIV, whether differences are impacted by method type, antiretroviral therapy use or other factors.

METHODS

We searched Ovid MEDLINE, POPLINE and PubMed.gov for studies published between January 1, 2000, and August 31, 2016. Inclusion criteria comprised prospective data of WLHIV, nonbarrier method continuation as an outcome measure, and recorded method switching and/or discontinuation.

RESULTS

Of 939 citations screened, 22 articles from 18 studies were eligible. For studies with comparator groups, data quality was moderate overall based on Grading of Recommendations, Assessment, Development and Evaluations and Newcastle-Ottawa Quality Assessment scales. Of four studies comparing women by HIV serostatus, two showed higher rates of contraceptive continuation among WLHIV versus uninfected women, while two others detected lower continuation rates for the same comparison. Generally, baseline method continuation exceeded 60% for studies with >12months of follow-up. Studies providing contraception had higher continuation rates than studies not providing contraception, while women allocated to contraceptive methods in trials had similar continuation rates to those choosing contraceptive methods. Across all studies, continuation rates differed by method and context, with the copper intrauterine device showing greatest variability between sites (51%-91% continuation rates at ≥12months). Implant continuation rates were ≥86%, though use was low relative to other methods and limited to few studes.

CONCLUSIONS

Contraceptive continuation among WLHIV differs by method and context. More longitudinal studies with contraceptive continuation as a measured outcome following ≥12months are needed to strengthen integration of RH and HIV care.

Concomitant contraceptive implant and efavirenz use in women living with HIV: perspectives on current evidence and policy implications for family planning and HIV treatment guidelines

Introduction: Preventing unintended pregnancies is important among all women, including those living with HIV. Increasing numbers of women, including HIV-positive women, choose progestin-containing subdermal implants, which are one of the most effective forms of contraception. However, drug–drug interactions between contraceptive hormones and efavirenz-based antiretroviral therapy (ART) may reduce implant effectiveness. We present four inter-related perspectives on this issue.

Discussion: First, as a case study, we discuss how limited data prompted country-level guidance against the use of implants among women concomitantly using efavirenz in South Africa and its subsequent negative effects on the use of implants in general. Second, we discuss the existing clinical data on this topic, including the observational study from Kenya showing women using implants plus efavirenz-based ART had three-fold higher rates of pregnancy than women using implants plus nevirapine-based ART. However, the higher rates of pregnancy in the implant plus efavirenz group were still lower than the pregnancy rates among women using common alternative contraceptive methods, such as injectables. Third, we discuss the four pharmacokinetic studies that show 50–70% reductions in plasma progestin concentrations in women concurrently using efavirenz-based ART as compared to women not on any ART. These pharmacokinetic studies provide the biologic basis for the clinical findings. Fourth, we discuss how data on this topic have marked implications for both family planning and HIV programmes and policies globally.

Conclusion: This controversy underlines the importance of integrating family planning services into routine HIV care, counselling women appropriately on increased risk of pregnancy with concomitant implant and efavirenz use, and expanding contraceptive method mix for all women. As global access to ART expands, greater research is needed to explore implant effectiveness when used concomitantly with newer ART regimens. Data on how HIV-positive women and their partners choose contraceptives, as well as information from providers on how they present and counsel patients on contraceptive options are needed to help guide policy and service delivery. Lastly, greater collaboration between HIV and reproductive health experts at all levels are needed to develop successful strategies to ensure the best HIV and reproductive health outcomes for women living with HIV.

Drug interactions and the role of pharmacokinetic trials in guiding choices in first-line HIV therapy in low-income and middle-income countries

PURPOSE OF REVIEW

Low- and middle-income countries (LMICs) face specific challenges in the treatment of people living with HIV. Drug-drug interactions (DDIs) involving antiretrovirals (ARVs) are prevalent in all settings and have considerable potential to cause clinical harm to patients via toxicity or reduced efficacy of treatment. Differing comorbidities, endemic infections and traditional medicines may complicate ARV therapy (ART) in LMICs, which usually takes a public health approach in these settings, with fewer alternative regimens available. This review discusses the issues surrounding pharmacokinetic DDI studies and their application to ART in LMICs, with particular reference to first-line ART regimens.

RECENT FINDINGS

Pharmacokinetic studies with clinical endpoints are the gold standard for informing management of DDIs; however, data relevant to LMICs are sparse and of low quality. There is significant potential for clinically relevant DDIs between ARVs and antimalarials, antimycobacterials and drugs used in the treatment of neglected tropical diseases.

SUMMARY

Many pharmacokinetic studies are difficult to interpret in LMICs due to differences in patient factors including weight, disease state and genetic polymorphisms. DDI studies relevant to LMICs may also be lacking due to the neglected nature of relevant comorbidities. The ARVs currently available as first-line ART in LMICs are among those with highest propensity for DDIs.

Brief Report: Dapivirine Vaginal Ring Use Does Not Diminish the Effectiveness of Hormonal Contraception

OBJECTIVE

To evaluate the potential for a clinically relevant drug-drug interaction with concomitant use of a dapivirine vaginal ring, a novel antiretroviral-based HIV-1 prevention strategy, and hormonal contraception by examining contraceptive efficacies with and without dapivirine ring use.

DESIGN

A secondary analysis of women participating in MTN-020/ASPIRE, a randomized, double-blind, placebo-controlled trial of the dapivirine vaginal ring for HIV-1 prevention.

METHODS

Use of a highly effective method of contraception was an eligibility criterion for study participation. Urine pregnancy tests were performed monthly. Pregnancy incidence by arm was calculated separately for each hormonal contraceptive method and compared using an Andersen-Gill proportional hazards model stratified by site and censored at HIV-1 infection.

RESULTS

Of 2629 women enrolled, 2310 women returned for follow-up and reported using a hormonal contraceptive method at any point during study participation (1139 in the dapivirine arm and 1171 in the placebo arm). Pregnancy incidence in the dapivirine arm versus placebo among women using injectable depot medroxyprogesterone acetate was 0.43% vs. 0.54%, among women using injectable norethisterone enanthate was 1.15% vs. 0%, among women using hormonal implants was 0.22% vs. 0.69%, and among women using oral contraceptive pills was 32.26% vs. 28.01%. Pregnancy incidence did not differ by study arm for any of the hormonal contraceptive methods.

CONCLUSIONS

Use of the dapivirine ring does not reduce the effectiveness of hormonal contraceptives for pregnancy prevention. Oral contraceptive pill use was associated with high pregnancy incidence, potentially because of poor pill adherence. Injectable and implantable methods were highly effective in preventing pregnancy.

Current and future contraceptive options for women living with HIV

INTRODUCTION

Among women living with HIV, half of the pregnancies are unintended. Effective contraception can prevent unintended pregnancies and consequently reduce maternal mortality and perinatal transmission of HIV. While contraceptive options available for all women also apply to women living with HIV, specific considerations exist to the use of contraception by women living with HIV.

AREAS COVERED

First, general principles guiding the use of contraception among women living with HIV are discussed, such as choice, method mix, relative effectiveness, and drug-drug interactions. Second, a detailed discussion of each contraceptive method and issues surrounding the use of that method, such as drug-drug interactions, follows. Third, future contraceptive options in advanced development for use by women or men are briefly discussed.

EXPERT OPINION

Contraceptive methods available to all women should also be accessible to women living with HIV. When the relative effectiveness of a contraceptive method is reduced, for example due to drug-drug interactions with antiretrovirals, the method should still be made available to women living with HIV with the appropriate information sharing and counseling. Greater research on various aspects of contraceptive use by women living with HIV and more comprehensive testing of co-administration of hormonal contraceptives and common medications used by these women are warranted.

Efavirenz decreases etonogestrel exposure: a pharmacokinetic evaluation of implantable contraception with antiretroviral therapy

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.

Practice Bulletin No. 167: Gynecologic Care for Women and Adolescents With Human Immunodeficiency Virus

In the United States in 2013, there were an estimated 226,000 women and adolescents living with human immunodeficiency virus (HIV) infection (1). Women with HIV are living longer, healthier lives, so the need for routine and problem-focused gynecologic care has increased. The purpose of this document is to educate clinicians about basic health screening and care, family planning, prepregnancy care, and managing common gynecologic problems for women and adolescents who are infected with HIV. For information on screening guidelines, refer to the American College of Obstetricians and Gynecologists' Committee Opinion No. 596, Routine Human Immunodeficiency Virus Screening (2).

High Variability of Hormonal Levels and No Clinically Relevant Interaction Between Ethinyl Estradiol, Desogestrel and Lopinavir/Ritonavir in a Small Sample of HIV-positive Adolescents

BACKGROUND

We report the pharmacokinetic interactions of combined oral contraceptive (COC) containing ethinyl estradiol (EE2)/desogestrel (DSG) with lopinavir/ritonavir (LPV/r) in 16 HIV-positive adolescents.

METHODS

We measured Ctrough of EE2 and etonogestrel (ENG), the active metabolite of DSG, in HIV-positives on LPV/r-based ART; Ctrough of LPV/r with and without COC; endogenous progesterone. EE2/ENG levels were compared with our own historical data of HIV-negative controls.

RESULTS

Ctrough of EE2 and ENG varied from 3 to 57 pg/mL and from 1051 to 5000 pg/mL, respectively. The geometric mean ratios (GMR) of Ctrough in HIV-positives on LPV/r with COC versus HIV-negative controls with COC only were 0.68 (95% CI: 0.42 to 1.08) or 32% decreased (P = 0.10) for EE2; and 1.08 (95% CI: 0.73 to 1.60) or 8% increased (P = 0.68) for ENG. Endogenous progesterone was <1.0 ng/mL in all participants, consistent with anovulation. Ctrough of LPV decreased statistically insignificantly with COC and remained above the desired therapeutic minimum of 1.0 mg/L in all.

CONCLUSIONS

The study found no clinically relevant interaction between EE2/DSG and LPV/r. This was supported by suppressed ovulation, assessed by low endogenous progesterone levels in all participants; and preserved antiretroviral activity, assessed by LPV/r levels above the desired therapeutic minimum in all participants. However, the high variability of hormonal levels warrants individual monitoring and further investigation. Condom use should always be encouraged for infection prevention.

Drug-Drug Interactions, Effectiveness, and Safety of Hormonal Contraceptives in Women Living with HIV

Family planning options, including hormonal contraceptives, are essential for improving reproductive health among the more than 17 million women living with HIV worldwide. For these women, prevention of unintended pregnancy decreases maternal and child mortality, as well as reduces the risk of perinatal HIV transmission. Similarly, treatment of HIV with antiretroviral therapy (ART) is essential for reducing morbidity and mortality among HIV-positive individuals, as well as preventing HIV transmission between sexual partners or from mother to child. Importantly, despite the benefits of hormonal contraceptives, barriers to effective family planning methods exist for HIV-positive women. Specifically, drug-drug interactions can occur between some antiretroviral medications and some hormonal contraceptives, which may influence both contraceptive efficacy and tolerability. In addition, safety concerns have been raised about the impact of hormonal contraceptives on HIV disease progression, tolerability, and the risk of female-to-male HIV transmission. This review article summarizes the potential for drug-drug interactions, tolerability, and contraceptive effectiveness when hormonal contraceptives are combined with ART. In addition, the evidence surrounding the influence of hormonal contraceptives on HIV transmission and HIV disease progression in women living with HIV are summarized.

Contraception for HIV-Infected Adolescents

Access to high-quality reproductive health care is important for adolescents and young adults with HIV infection to prevent unintended pregnancies, sexually transmitted infections, and secondary transmission of HIV to partners and children. As perinatally HIV-infected children mature into adolescence and adulthood and new HIV infections among adolescents and young adults continue to occur in the United States, medical providers taking care of such individuals often face issues related to sexual and reproductive health. Challenges including drug interactions between several hormonal methods and antiretroviral agents make decisions regarding contraceptive options more complex for these adolescents. Dual protection, defined as the use of an effective contraceptive along with condoms, should be central to ongoing discussions with HIV-infected young women and couples wishing to avoid pregnancy. Last, reproductive health discussions need to be integrated with discussions on HIV care, because a reduction in plasma HIV viral load below the level of detection (an "undetectable viral load") is essential for the individual's health as well as for a reduction in HIV transmission to partners and children.

Antiretroviral Therapy for Prevention of Human Immunodeficiency Virus Infection

Human immunodeficiency virus (HIV) infection is considered a chronic medical condition. Several new drugs are available, including fixed-dose combination tablets, that have greatly simplified combination antiretroviral therapy (ART) regimens to treat HIV, while increasing the life-expectancy of infected individuals. In the last decade, multiple well-regarded studies have established the benefits of using ART in high-risk, HIV-negative persons to prevent HIV acquisition. The primary care provider must not only understand commonly encountered issues pertaining to ART, such as toxicities and drug interactions, but also needs to be aware of using ART for HIV prevention.

Bleeding patterns of HIV-infected women using an etonogestrel-releasing contraceptive implant and efavirenz-based or lopinavir/ritonavir-based antiretroviral therapy

OBJECTIVES

The use of progestogen-only contraceptives may cause a change in bleeding pattern, which is a common cause of discontinuation of these methods. Co-administration with some antiretroviral therapies (ART) changes the bioavailability of the etonogestrel (ENG)-releasing contraceptive implant, possibly affecting the bleeding pattern. Bleeding patterns were evaluated in HIV-positive users of the ENG implant co-administered with two common ART regimens.

METHODS

Forty-five HIV-positive women who wished to use an ENG implant were included in this study: 15 had received zidovudine/lamivudine (AZT/3TC) + lopinavir/ritonavir (LPV/r) for ≥3 months (LPV/r-based ART group), 15 had received AZT/3TC + efavirenz (EFV) for ≥3 months (EFV-based ART group), and 15 had not received ART (non-ART group). Bleeding patterns were evaluated at 3 and 6 months after implant placement using a standard bleeding calendar.

RESULTS

Amenorrhoea and infrequent bleeding rates were higher in the LPV/r-based ART group (50% and 36%, respectively) than in the other groups (non-ART group, 36% and 29%, respectively; EFV-based ART group, 7% and 14.5%, respectively; p = 0.01). The EFV-based ART group more frequently had regular bleeding (71.5%) compared with the other groups (LPV/r-based ART group, 7%; non-ART group, 21%; p = 0.01). The proportions of women with frequent and prolonged bleeding were similar (p > 0.05) in the three groups.

CONCLUSIONS

The co-administration of EFV-based or LPV/r-based ART with the ENG implant affected the expected bleeding patterns during use of the implant, although unfavourable bleeding (frequent and prolonged) was not associated with the medications under evaluation.

Reproductive intentions and family planning practices of pregnant HIV-infected Malawian women on antiretroviral therapy

The objective of this study was to describe the pregnancy intentions of pregnant HIV-infected Malawian women on antiretroviral therapy (ART) for at least 6 months prior to the current pregnancy, and to assess whether time on ART was associated with pregnancy intention. We conducted a cross-sectional analysis of HIV-infected Malawian women receiving antenatal care at a government hospital with a survey assessing ART history, reproductive history, and family planning use at conception. We used Pearson's chi-square tests and Fisher's exact tests to compare these parameters between women on ART greater than 24 months with those on ART less than 24 months. Modified Poisson regression was performed to assess the association between time on ART and pregnancy intention. Most women (75%) reported that their current pregnancy was unintended, defined as either Mistimed (21%) or Unwanted (79%). Women on ART for longer than 2 years were more likely to report an unintended pregnancy (79% versus 65%, p = .03), though there was no significant association between time on ART and pregnancy intention in multivariate analysis. Most women (79%) were using contraception at the time of conception, with condoms being most popular (91%), followed by injectables (9%) and the implant (9%). HIV-infected women on ART continue to experience high rates of unintended pregnancy in the Option B+ era. As Option B+ continues to be implemented in Malawi and increasing numbers of HIV-infected women initiate lifelong ART, ensuring that the most effective forms of contraception are accessible is necessary to decrease unintended pregnancy.

Drug transporters in tissues and cells relevant to sexual transmission of HIV: Implications for drug delivery

Efflux and uptake transporters of drugs are key regulators of the pharmacokinetics of many antiretroviral drugs. A growing body of literature has revealed the expression and functionality of multiple transporters in female genital tract (FGT), colorectal tissue, and immune cells. Drug transporters could play a significant role in the efficacy of preventative strategies for HIV-1 acquisition. Pre-exposure prophylaxis (PrEP) is a promising strategy, which utilizes topically (vaginally or rectally), orally or other systemically administered antiretroviral drugs to prevent the sexual transmission of HIV to receptive partners. The drug concentration in the receptive mucosal tissues and target immune cells for HIV is critical for PrEP effectiveness. Hence, there is an emerging interest in utilizing transporter information to explain tissue disposition patterns of PrEP drugs, to interpret inter-individual variability in PrEP drug pharmacokinetics and effectiveness, and to improve tissue drug exposure through modulation of the cervicovaginal, colorectal, or immune cell transporters. In this review, the existing literature on transporter expression, functionality and regulation in the transmission-related tissues and cells is summarized. In addition, the relevance of transporter function for drug delivery and strategies that could exploit transporters for increased drug concentration at target locales is discussed. The overall goal is to facilitate an understanding of drug transporters for PrEP optimization.

Unintended Pregnancies Observed With Combined Use of the Levonorgestrel Contraceptive Implant and Efavirenz-based Antiretroviral Therapy: A Three-Arm Pharmacokinetic Evaluation Over 48 Weeks

BACKGROUND

Levonorgestrel subdermal implants are preferred contraceptives with an expected failure rate of <1% over 5 years. We assessed the effect of efavirenz- or nevirapine-based antiretroviral therapy (ART) coadministration on levonorgestrel pharmacokinetics.

METHODS

This nonrandomized, parallel group, pharmacokinetic evaluation was conducted in three groups of human immunodeficiency virus-infected Ugandan women: ART-naive (n = 17), efavirenz-based ART (n = 20), and nevirapine-based ART (n = 20). Levonorgestrel implants were inserted at baseline in all women. Blood was collected at 1, 4, 12, 24, 36, and 48 weeks. The primary endpoint was week 24 levonorgestrel concentrations, compared between the ART-naive group and each ART group by geometric mean ratio (GMR) with 90% confidence interval (CI). Secondary endpoints included week 48 levonorgestrel concentrations and unintended pregnancies.

RESULTS

Week 24 geometric mean levonorgestrel concentrations were 528, 280, and 710 pg/mL in the ART-naive, efavirenz, and nevirapine groups, respectively (efavirenz: ART-naive GMR, 0.53; 90% CI, .50, .55 and nevirapine: ART-naive GMR, 1.35; 90% CI, 1.29, 1.43). Week 48 levonorgestrel concentrations were 580, 247, and 664 pg/mL in the ART-naive, efavirenz, and nevirapine groups, respectively (efavirenz: ART-naive GMR, 0.43; 90% CI, .42, .44 and nevirapine: ART-naive GMR, 1.14; 90% CI, 1.14, 1.16). Three pregnancies (3/20, 15%) occurred in the efavirenz group between weeks 36 and 48. No pregnancies occurred in the ART-naive or nevirapine groups.

CONCLUSIONS

Within 1 year of combined use, levonorgestrel exposure was markedly reduced in participants who received efavirenz-based ART, accompanied by contraceptive failures. In contrast, nevirapine-based ART did not adversely affect levonorgestrel exposure or efficacy.

CLINICAL TRIALS REGISTRATION

NCT01789879.

Pharmacogenetics of non-nucleoside reverse transcriptase inhibitors (NNRTIs) in resource-limited settings: Influence on antiretroviral therapy response and concomitant anti-tubercular, antimalarial and contraceptive treatments

The burden of human immunodeficiency virus (HIV) is mainly concentrated to resources-limited countries where the response to available antiretroviral therapy is often limited by the occurrence of toxicity or by the emergence of HIV drug resistance. Efavirenz and nevirapine are the antiretroviral drugs most prescribed in resources-limited countries as part of antiretroviral combination therapy. Their metabolism and conjugation are largely influenced by enzymatic genetic polymorphisms. The genetic variability of their metabolism could be associated to different metabolic phenotypes causing reduced patients' adherence because of toxicity or drug-drug interactions with concomitant therapies. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to efavirenz and nevirapine, the influence of concomitant anti-tubercular, anti-malarial or contraceptive treatments, and the impact of human genetic variation and drug-drug interaction on the virologic and immunologic response to antiretroviral therapy in resources-limited countries.

Effectiveness of hormonal contraception in HIV-infected women using antiretroviral therapy

OBJECTIVE

The objective of this study is to assess whether antiretroviral therapy (ART) may diminish the effectiveness of hormonal contraceptive methods.

METHODS

Using data from 5153 HIV-infected women followed prospectively for 1-3 years in three HIV prevention studies in Africa, we compared incident pregnancy rates by contraceptive method (implant, injectable, oral or none) and ART use. Multivariable Cox regression models were used to determine adjusted hazard ratios (aHRs) and test interactions between each method and ART use.

RESULTS

During follow-up, 9% of women ever used implants, 40% used injectables and 14% used oral contraceptives; 31% of women ever used ART, mostly nevirapine (75% of ART users) or efavirenz-based (15%). Among women not using contraception, pregnancy rates were 13.2 and 22.5 per 100 women-years for those on and not on ART, respectively. Implants greatly reduced the incidence of pregnancy among both women on ART [aHR 0.06, 95% confidence interval (95% CI) 0.01-0.45] and not on ART (aHR 0.05, 95% CI 0.02-0.11). Injectables (aHR 0.18 on ART and aHR 0.20 not on ART) and oral contraceptives (aHR 0.37 on ART and aHR 0.36 not on ART) also reduced pregnancy risk, though by lesser degrees. ART use did not significantly diminish contraceptive effectiveness, although all methods showed nonstatistically significant reduced effectiveness when concurrently using efavirenz.

CONCLUSION

Hormonal contraceptive methods are highly effective in reducing pregnancy risk in HIV-infected women, including those concurrently using ART. Studies of potential interactions between ART and contraceptives should evaluate real-world effectiveness of contraceptive methods; in this study, implants were the most effective method to prevent pregnancy, even during ART use.