Drug interactions between Ilosone and Lipitor

GENERALLY AVOID: Some macrolide antibiotics inhibit CYP450 3A4 and may elevate the plasma concentrations of HMG-CoA reductase inhibitors that are metabolized by the isoenzyme. Macrolides that may significantly inhibit CYP450 3A4 include troleandomycin, erythromycin, and clarithromycin. There have been case reports of patients treated with lovastatin or simvastatin who developed severe myopathy or rhabdomyolysis following the addition of a macrolide, usually erythromycin. Plasma levels of HMG-CoA reductase inhibitory activity were significantly elevated in these patients, up to several-fold in many cases. Similar pharmacokinetic changes have been reported in studies with erythromycin and simvastatin and, to a lesser extent, with clarithromycin or erythromycin and atorvastatin. The interaction was also 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. MANAGEMENT: Because of the increased risk of musculoskeletal toxicity associated with high levels of HMG-CoA reductase inhibitory activity in plasma, macrolide therapy should be carefully selected in patients treated with atorvastatin, cerivastatin, lovastatin, simvastatin, and red yeast rice (which contains lovastatin). Azithromycin and dirithromycin may be safer alternatives in these patients, since they are generally believed to have little, if any, effect on CYP450 3A4. However, azithromycin has been implicated in a single case of rhabdomyolysis during lovastatin treatment. 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.