Detectable Tenofovir Levels in Breast-Feeding Infants of Mothers Exposed to Topical Tenofovir.

Lactation studies are necessary evaluations of medications for reproductive-age women. We evaluated pharmacokinetics (PK), pharmacodynamics, safety, and adherence profiles associated with 7 days of 1% tenofovir (TFV) vaginal gel use during lactation. Tenofovir levels (maternal/infant serum, milk) and anti-HIV activity (milk), adverse events (AEs), and adherence were measured for 17 HIV-1-seronegative breast-feeding mother-infant pairs. Tenofovir use was well-tolerated and detected at low levels in maternal serum, milk, and infant serum but demonstrated no anti-HIV activity in milk.