DDI risk during oral lead in phase
Intramuscular administration of cabotegravir and rilpivirine has the
advantage of eliminating first pass metabolism and DDIs occurring at the
gastrointestinal level. However, there are a number of drug interactions
for cabotegravir and rilpivirine that are clinically relevant during the
oral lead-in phase. Divalent metal cations (e.g. Ca2+,
Al2+, Mg2+, Fe2+,
Zn2+) for example calcium containing antacids and some
multivitamins chelate with cabotegravir in the gut and can decrease
absorption and therefore dosing with oral cabotegravir must be separated
by at least 2 hours before or 4 hours after such medications .
Rilpivirine requires an acidic gastric environment to facilitate
absorption and therefore proton-pump inhibitors decrease rilpivirine
exposure when taken orally .