Drug interactions between Lipitor and Prevacid

lansoprazole ↔ atorvastatin

Applies to:Prevacid (lansoprazole) and Lipitor (atorvastatin)

MONITOR: A case report suggests that coadministration with esomeprazole may increase the plasma concentrations of atorvastatin and the associated risk of myopathy. The proposed mechanism is competitive inhibition of intestinal P-glycoprotein, resulting in decreased drug secretion into the intestinal lumen and increased drug bioavailability. Another, perhaps minor mechanism is competitive inhibition of CYP450 3A4 metabolism. The interaction was suspected in a patient treated with atorvastatin (more than 1 year) and esomeprazole (6 weeks) who developed rhabdomyolysis with AV block two days after the addition of clarithromycin. The patient reported experiencing symptoms of increased fatigue, mild chest pain, and shortness of breath that coincided with the initiation of esomeprazole approximately six weeks prior to admission. Theoretically, the interaction may also occur with other proton pump inhibitors like lansoprazole, omeprazole, and pantoprazole and HMG-CoA reductase inhibitors like lovastatin and simvastatin, since these drugs are all substrates of P-glycoprotein and CYP450 3A4.

MANAGEMENT: Because of the increased risk of musculoskeletal toxicity associated with high levels of HMG-CoA reductase inhibitory activity in plasma, patients treated with atorvastatin, lovastatin, simvastatin, and red yeast rice (which contains lovastatin) should be monitored more closely during concomitant use of proton pump inhibitors. All patients treated with HMG-CoA reductase inhibitors should be advised to promptly report to their physician any unexplained muscle pain, tenderness, or weakness, particularly if accompanied by malaise or fever. Therapy should be discontinued if creatine kinase is markedly elevated or if myopathy is suspected or diagnosed.