Drug Interactions between indinavir and sofosbuvir / velpatasvir / voxilaprevir

ADJUST DOSING INTERVAL: According to the manufacturer, coadministration with a meal high in calories, fat, and protein reduces the absorption of indinavir. In ten patients given indinavir in this manner, the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of indinavir decreased by an average of 84% and 77%, respectively. In contrast, grapefruit juice may have only minor effects on the oral bioavailability of indinavir. The manufacturer's package labeling states that administration of a single 400 mg dose of indinavir with 8 oz. of grapefruit juice decreased indinavir AUC by an average of 26%. Likewise, a study consisting of 14 HIV-infected subjects found no uniform nor significant changes in steady-state indinavir AUC during administration with double-strength grapefruit juice compared to water. There was, however, a delay in absorption (Tmax) due to grapefruit juice that is unlikely to be of clinical significance.

MANAGEMENT: To ensure maximal oral absorption, indinavir should be administered without food but with water 1 hour before or 2 hours after a meal. Alternatively, indinavir may be administered with other liquids such as skim milk, juice, coffee, or tea, or with a light meal (e.g., dry toast with jelly, juice, and coffee with skim milk and sugar; corn flakes, skim milk and sugar).

ADJUST DOSING INTERVAL: Administration with food enhances the oral bioavailability of sofosbuvir, velpatasvir, and voxilaprevir. Relative to fasting conditions, mean sofosbuvir systemic exposure (AUC) increased by 64% to 144%, mean velpatasvir AUC increased by 40% to 166%, and mean voxilaprevir AUC increased by 112% to 435% when the combined sofosbuvir/velpatasvir/voxilaprevir formulation is administered with food.

MANAGEMENT: Sofosbuvir/velpatasvir/voxilaprevir should be administered with food.

The recommended maximum number of medicines in the 'protease inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'protease inhibitors' category:

• indinavir
• sofosbuvir/velpatasvir/voxilaprevir

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.