(HealthDay)—For HIV-1-uninfected members of serodiscordant couples, tenofovir disoproxil fumarate (TDF) used as preexposure prophylaxis (PrEP) is associated with a small decrease in estimated glomerular filtration rate (eGFR), according to a study published online Dec. 22 in JAMA Internal Medicine.

Kenneth K. Mugwanya, M.B.Ch.B., from the University of Washington in Seattle, and colleagues examined whether TDF-based PrEP causes eGFR decline in HIV-1-uninfected adults. The authors conducted a per-protocol safety analysis of changes in eGFR in a randomized, placebo-controlled trial of daily oral TDF and emtricitabine (FTC)-TDF PrEP among heterosexual HIV-1-uninfected members of serodiscordant couples. Of the 4,640 participants (63 percent men), 1,548 were assigned to once-daily TDF, 1,545 to FTC-TDF, and 1,547 to placebo.

During a median follow-up of 18 months, the researchers found average decreases in eGFR attributable to PrEP versus placebo of −1.23 mL/min/1.73 m² (P = 0.004) for TDF and −1.59 mL/min/1.73 m² (P < 0.001) for FTC-TDF. By one month after randomization the difference in mean eGFR appeared between PrEP and ; it was stable through 12 months and decreased thereafter. The proportion of people with a confirmed decrease of eGFR of 25 percent or greater from baseline to 12 or 24 months was not significantly different in the TDF or FTC-TDF groups versus the .

"Our data support the safety of TDF-based PrEP in heterosexual populations as part of a comprehensive HIV-1 prevention package," the authors write.

The study medication was donated by Gilead Sciences.