Drug Interaction Report

MONITOR: Coadministration with lenacapavir may increase the plasma concentrations of drugs that are substrates of the efflux transporters P-glycoprotein (P-gp) and/or breast cancer resistance protein (BCRP). Lenacapavir is an inhibitor of P-gp and BCRP. In pharmacokinetic studies in subjects without HIV, coadministration of oral lenacapavir (600 mg twice daily for 2 days, then single 600 mg dose) with the P-gp substrate tenofovir alafenamide increased the peak plasma concentration (Cmax) and systemic exposure (AUC) of tenofovir alafenamide by 24% and 32%, respectively. In addition, under similar conditions, coadministration of lenacapavir with the BCRP substrate rosuvastatin (single 5 mg dose) led to an increase in rosuvastatin Cmax and AUC by 57% and 31%, respectively. However, these changes for tenofovir alafenamide and rosuvastatin are not reported to be clinically significant.

MANAGEMENT: Caution and monitoring are advised if lenacapavir is used concomitantly with drugs that are substrates of the transporters P-gp and/or BCRP, particularly sensitive substrates, or those with a narrow therapeutic range. Dose adjustments or alternative therapy may be necessary if an interaction is suspected.

ADJUST DOSING INTERVAL: Oral cladribine may increase the bioavailability of other drugs, which may increase the risk or severity of adverse reactions. Cladribine tablets may contain hydroxypropyl betadex, which could form a complex with the active ingredients of other drugs, especially agents with low solubility. The clinical relevance of this interaction remains unknown.

MANAGEMENT: Administration of oral cladribine should be separated from any other oral drug by at least 3 hours.