Vermectin Drug Interactions

Ivermectin is principally metabolized by the cytochrome P450 (CYP) isoenzyme 3A4 and, to a lesser extent, CYP2D6 and 2E1. Ivermectin does not inhibit CYP isoenzymes 3A4, 2D6, 2C9, 1A2, and 2E1.
Drugs with γ-Aminobutyric acid (GABA)-Potentiating Activity: Concurrent therapy with ivermectin and drugs with GABA-potentiating activity (e.g., barbiturates, benzodiazepines, sodium oxybate, valproic acid) is not recommended.
Benzodiazepines: Ivermectin may potentiate the activity of benzodiazepines. Concurrent therapy with ivermectin and benzodiazepines is not recommended.
Drugs Affecting or Affected by P-glycoprotein Transport: Ivermectin appears to be a substrate of the P-glycoprotein transport system; thus, interactions with inhibitors (e.g., amiodarone, carvedilol, clarithromycin, cyclosporine, erythromycin, itraconazole, ketoconazole, quinidine, ritonavir, tamoxifen, verapamil) or inducers (e.g., amprenavir, clotrimazole, phenothiazines, rifampin, ritonavir, St. John's wort) of the P-glycoprotein transporter are theoretically possible.
Anticoagulants: There have been postmarketing reports of elevated international normalized ratio (INR) when ivermectin was used concomitantly with warfarin.