Increased plasma conc of drugs that are primarily metabolized by CYP3A &/or CYP2D6 or are substrates of P-gp, BCRP, MATE1, OATP1B1 or OATP1B3. Lowered plasma conc w/ CYP3A inducers. Increased plasma conc w/ CYP3A inhibitors. Loss of therapeutic effect & development of resistance w/ efavirenz, etravirine, nevirapine; carbamazepine, phenobarb, phenytoin; rifampin; systemic dexamethasone or other systemic corticosteroids; St. John's wort. Potential decreased darunavir conc w/ rifapentine. Potential changes in exposures w/ eslicarbazepine, oxcarbazepine. Increased conc w/ itraconazole, ketoconazole, posaconazole; antibacterials (clarithromycin, erythromycin, telithromycin). Increased conc of maraviroc; alfuzosin; ranolazine; dronedarone, antiarrhythmics, digoxin; antibacterial (clarithromycin, erythromycin, telithromycin); anticancer agents (eg, dasatinib, nilotinib, vinblastine, vincristine); apixaban, rivaroxaban; clonazepam; TCAs, trazodone; itraconazole, ketoconazole; colchicine; rifabutin; lurasidone, pimozide, antipsychotics (eg, perphenazine, risperidone, thioridazine), quetiapine; β-blockers; Ca-channel blockers; corticosteroids; bosentan; ergot derivatives; cisapride; elbasvir/grazoprevir; simeprevir; immunosuppressants; salmeterol; HMG-CoA reductase inhibitors, lomitapide; fentanyl, oxycodone, tramadol; PDE-5 inhibitors; ticagrelor; midazolam, triazolam, sedatives/hypnotics. Monitor INR when co-administering w/ warfarin. Didanosine should be administered 1 hr before or 2 hr after Prezcobix (administered w/ food). Potential decrease of antimalarial efficacy of artemether or lumefantrine, or potential QT prolongation. Additional or alternative (non-hormonal) forms of contraception should be considered when estrogen-containing contraceptives are co-administered w/ Prezcobix. Potential for hyperkalemia w/ drospirenone. Dose adjustment may be needed for buprenorphine, buprenorphine/naloxone or methadone.