Statin Update

• Statin Induced Myopathy
• Myalgias are reported by 10 to 20% of patients who take statins
• The incidence of severe myotoxicity (CK > 10 times the upper limit of normal, associated with muscle symptoms leading to hospitalization) is estimated at 0.1 to 1.0%, or 0.4 to 1.1 per 10,000 patient-years.
• Risk factors for the development of a statin-associated myopathy:
• Concurrent medications
• e.g., fibrates and calcium-channel blockers
• Older age
• Hypothyroidism
• Hepatic dysfunction
• High BMI
• The risk of a statin-induced myopathy is dose-dependent
• The risk among patients who receive high-dose therapy is higher by a factor of 10 than the risk among patients who receive more moderate doses
• Simvastatin may be particularly notorious in this regard (high dose [greater than 40mg daily] = high risk of myopathy)
• Drugs that compete with the cytochrome P-450 system could augment statin myotoxicity
• Amlodipine, doxazosin, and finasteride all use this pathway and thus render patients vulnerable to the myotoxic effects of simvastatin
• Gemfibrozil poses an additional problem, since it may interfere with the hepatic uptake of simvastatin
• Concurrent therapy with statins and gemfibrozil has been associated with an increased risk of myopathy; in one study, the average incidence of rhabdomyolysis per 10,000 patient-years increased from 0.49 to 18.73

Reference: http://www.nejm.org/doi/full/10.1056/NEJMcpc1110052?query=BUL

• No More Routine Monitoring of LFTs for patients on Statins
• New FDA guidelines for statins released last week
• Recommendation for routine monitoring of LFTs in patients taking statins was removed.
• Labels now recommend that LFTs be checked before starting statin therapy and as clinically indicated thereafter.
• The FDA has concluded that serious liver injury with statins is rare and unpredictable in individual patients, and that routine periodic monitoring of liver enzymes does not appear to be effective in detecting or preventing serious liver injury.

Reference: http://www.fda.gov/Drugs/DrugSafety/ucm293101.htm