Drug Interactions between pitavastatin and Rifadin IV

ADJUST DOSE: Coadministration with rifampin may significantly increase the plasma concentrations of pitavastatin. The proposed mechanism is rifampin inhibition of pitavastatin hepatic uptake via organic anion transporting polypeptide (OATP) 1B1. In healthy volunteers, administration of pitavastatin (4 mg once daily) in combination with rifampin (600 mg once daily) for 5 days resulted in a 2-fold increase in pitavastatin peak plasma concentration (Cmax) and a 29% increase in systemic exposure (AUC) compared to administration of pitavastatin alone. High levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death. Pitavastatin did not significantly affect the pharmacokinetics of rifampin.

MANAGEMENT: Pitavastatin dosage should not exceed 2 mg daily when used in combination with rifampin. All patients receiving statin therapy should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed.