HIV-1 Virologic Rebound Due to Coadministration of Divalent Cations and Bictegravir

A potential drug-drug interaction exists between divalent and trivalent cations (Ca²⁺, Fe³⁺, Mg²⁺, Al³⁺, Zn²⁺) and HIV-1 integrase strand transfer inhibitors (INSTIs). There are limited case reports describing the clinical significance of this potential interaction and none to our knowledge identifying zinc co-administration with INSTIs. In this report we present a patient taking bictegravir/emtricitabine/tenofovir alafenamide who became viremic after ingesting zinc and calcium supplements and later was able to obtain virologic re-suppression after discontinuing supplements. This case represents a potential significant drug interaction between a commonly prescribed antiretroviral drug class and readily available over-the-counter divalent cation products.