Renal impairment in a large-scale HIV preexposure prophylaxis implementation cohort

An update on drug-drug interactions in older adults living with human immunodeficiency virus (HIV)

INTRODUCTION

People with HIV are living longer due to advances in antiretroviral therapy. With improved life expectancy comes an increased lifetime risk of comorbid conditions - such as cardiovascular disease and cancer - and polypharmacy. Older adults, particularly those living with HIV, are more vulnerable to drug interactions and adverse effects, resulting in negative health outcomes.

AREA COVERED

Antiretrovirals are involved in many potential drug interactions with medications used to treat common comorbidities and geriatric conditions in an aging population of people with HIV. We review the mechanisms and management of significant drug-drug interactions involving antiretroviral medications and non-antiretroviral medications commonly used among older people living with HIV. The management of these interactions may require dose adjustments, medication switches to alternatives, enhanced monitoring, and considerations of patient- and disease-specific factors.

EXPERT OPINION

Clinicians managing comorbid conditions among older people with HIV must be particularly vigilant to side effect profiles, drug-drug interactions, pill burden, and cost when optimizing treatment. To support healthier aging among people living with HIV, there is a growing need for antiretroviral stewardship, multidisciplinary care models, and advances that promote insight into the correlations between an individual, their conditions, and their medications.

Pregnancy and neonatal safety outcomes of timing of initiation of daily oral tenofovir disoproxil fumarate and emtricitabine pre-exposure prophylaxis for HIV prevention (CAP016): an open-label, randomised, non-inferiority trial

BACKGROUND

The safety of tenofovir disoproxil fumarate and emtricitabine as pre-exposure prophylaxis (PrEP) in pregnant women not living with HIV is uncertain. We aimed to compare pregnancy and neonatal outcomes in women exposed and not exposed to PrEP during pregnancy.

METHODS

In this single-site, open-label, randomised, non-inferiority trial in Durban, South Africa, we evaluated pregnancy and neonatal outcomes in pregnant women aged 18 years or older, not living with HIV, and at 14-28 weeks' gestation at the time of enrolment. Eligible participants were randomly assigned (1:1) using a computer-generated permuted block (block size of ten) randomisation list to immediate initiation or deferred initiation of PrEP until breastfeeding cessation. Participants in the immediate PrEP group received a monthly supply of once daily oral tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg. Participants in the deferred PrEP group received standard of care for HIV prevention. The primary outcomes were the occurrence of preterm live birth (<37 weeks gestational age) and very preterm birth (<34 weeks gestational age) determined by menstrual dating, low birthweight (<2500 g), very low birthweight (<1500 g), stillbirth (≥20 weeks gestational age), and small for gestational age (birthweight less than the tenth percentile). Post-natal safety outcomes will be reported elsewhere. We used binomial regression models to estimate risk differences and two-sided 90% CIs. Immediate PrEP was non-inferior to deferred PrEP if the upper bound of the 90% CI of the risk difference was less than the upper predefined non-inferiority margin for preterm birth (7·5%), very preterm birth (2·6%), low birthweight (5·5%), very low birthweight (1·2%), stillbirth (1·0%), and small for gestational age (3·7%). All outcomes were analysed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT3227731.

FINDINGS

Between Sept 25, 2017, and Dec 6, 2019, we screened 693 women, of whom 540 were randomly assigned to immediate PrEP (n=271) or deferred PrEP (n=269). The median gestational age was 19 weeks (IQR 15-23 for immediate PrEP and 16-23 for deferred PrEP). The risk difference between the immediate PrEP group and the deferred PrEP group for preterm birth was -4·7% (90% CI -10·7 to 1·2; immediate PrEP was non-inferior), for very preterm birth was 0·6% (-3·4 to 4·6; upper limit exceeded the non-inferiority margin), for low birthweight was 2·5% (-1·6 to 6·6; upper limit exceeded the non-inferiority margin), for very low birthweight was 0% (-1·4 to 1·4; upper limit exceeded the non-inferiority margin), for stillbirth was 1·2% (-1·5 to 3·8; upper limit exceeded the non-inferiority margin), and for small for gestational age was 0·9% (-1·2 to 2·9; immediate PrEP was non-inferior).

INTERPRETATION

In our study, PrEP was not associated with preterm birth or small for gestational age infants. Our data support the use of tenofovir disoproxil fumarate and emtricitabine in pregnancy and our reassuring findings can be used to allay safety concerns among pregnant women.

FUNDING

South African Medical Research Council and Gilead Sciences.

Impact on renal function of daily and on-demand HIV pre-exposure prophylaxis in the ANRS-PREVENIR study

OBJECTIVES

To assess the impact on the estimated glomerular filtration rate (eGFR) of different tenofovir disoproxil/emtricitabine dosing regimens for HIV pre-exposure prophylaxis (PrEP).

PATIENTS AND METHODS

We included in the study individuals with baseline eGFR > 50 mL/min/1.73 m2 who initiated PrEP in the ongoing ANRS-PREVENIR PrEP cohort. We retrospectively classified PrEP users in three groups: 'on-demand' (reported at ≥75% of study visits), 'daily' (≥75% of study visits) or 'switches'. We compared the area under curve (AUC) of the eGFR variation from baseline (ΔeGFR) between groups using analysis of covariance, and assessed factors associated with a negative AUC of ΔeGFR.

RESULTS

From May 2017 to October 2020, 1253 PrEP-naïve participants (98% of MSM) were included in the study with a median follow-up of 22 months. 499 (40%), 494 (39%) and 260 (21%) users were in the group daily, on-demand and switches, respectively, for a median number of pills taken per week of 6, 1.7 and 4. The mean AUC of the ΔeGFR was -1.09 mL/min/1.73 m2 in the daily PrEP group, -0.69 mL/min/1.73 m2 in the switches group and +0.18 mL/min/1.73 m2 with on-demand PrEP. In a model adjusted on baseline age and eGFR, the AUC of the ΔeGFR was significantly higher with on-demand PrEP compared to daily PrEP (P = 0.037). Independent factors associated with a negative AUC of ΔeGFR were a daily PrEP regimen, a switches regimen, an age > 40 years and a baseline eGFR≥90 mL/min/1.73 m².

CONCLUSIONS

On-demand PrEP dosing had a smaller impact on eGFR evolution than daily PrEP, but the difference was not clinically relevant.

Clinical Considerations in the Selection of Preexposure Prophylaxis for HIV Prevention in Canada

According to the Public Health Agency of Canada, approximately 62,050 people were living with HIV in Canada in 2018, and of those, 13% were undiagnosed. Currently, no single strategy provides complete protection or is universally effective across all demographic groups at risk for HIV. However, HIV preexposure prophylaxis (PrEP) is the newest HIV prevention strategy that shows promise. To date, two products have received an indication for PrEP by Health Canada: emtricitabine/tenofovir disoproxil fumarate (Truvada®; FTC/TDF) and emtricitabine/tenofovir alafenamide (Descovy®; FTC/TAF). Despite the high efficacy of these PrEP intervention methods, access to PrEP in Canada remains low. Identifying and addressing barriers to PrEP access, especially in high-risk groups, are necessary to reduce HIV transmission in Canada. While guidelines published by the Center for Disease Control and Prevention (CDC) include FTC/TAF information, the efficacy of FTC/TAF for PrEP has not yet been considered in Canada's clinical practice guidelines. Thus, the current paper reviews data regarding the use of FTC/TDF and FTC/TAF for PrEP, which may be useful for Canadian healthcare providers when counseling and implementing HIV prevention methods. The authors highlight these data in relation to various at-risk populations and review ongoing clinical trials investigating novel PrEP agents. Overall, FTC/TDF PrEP is effective for many populations, including men who have sex with men, transgender women, heterosexuals with partners living with HIV, and people who use drugs. While there is fewer data reported on the efficacy of FTC/TAF to date, recent clinical trials have demonstrated noninferiority of FTC/TAF in comparison to FTC/TDF. Notably, as studies have shown that FTC/TAF maintains renal function and bone mineral density to a greater extent than FTC/TDF, FTC/TAF may be a safer option for patients experiencing renal and/or bone dysfunction, for those at risk of renal and bone complications, and for those who develop FTC/TDF-related adverse events.

Fanconi syndrome in a patient receiving pre-exposure prophylaxis for HIV infection: case report

BACKGROUND

Tenofovir disoproxil is efficacious in the preventing HIV infection as part of a pre-exposure prophylaxis (PrEP) regimen. Although its use has been associated with impaired renal function, instances of Fanconi syndrome are extremely rare. This may change with increased uptake of PrEP.

METHODS

A 55-year-old male patient (he/him/his) was commenced on PrEP with a baseline estimated glomerular filtration rate (eGFR) of approximately 60mL/min/1.73m2.

RESULTS

Within 6months, he developed new and worsening proteinuria, glycosuria and aminoaciduria despite no apparent change in eGFR. PrEP was discontinued and his urinary abnormalities rapidly resolved. The patient remains off PrEP.

CONCLUSIONS

Fanconi syndrome is a rare, but known complication of tenofovir disoproxil. This is the first report related to PrEP in Australia. While tenofovir associated nephrotoxicity in patients taking PrEP is uncommon, the patient's age and pre-existing renal impairment placed him at substantially higher risk. At-risk patients need more frequent monitoring of their eGFR and proteinuria. Urinary protein to creatinine ratio is the preferred to dipstick testing for proteinuria and the latter does not readily detect the low molecular wight proteinuria characteristic of tenofovir toxicity. Early recognition of these patients is essential, as prompt cessation of PrEP can often reverse renal abnormalities.