5 WARNINGS AND PRECAUTIONS Skeletal muscle effects (e.g., myopathy and rhabdomyolysis): predisposing factors include advanced age (≥65), uncontrolled hypothyroidism, and renal impairment. Patients should be advised to promptly report to their physician any unexplained and/or persistent muscle pain, tenderness, or weakness. Pravastatin therapy should be discontinued if myopathy is diagnosed or suspected. (5.1, 8.5) Immune-Mediated Necrotizing Myopathy (IMNM): There have been rare reports of IMNM, an autoimmune myopathy, associated with statin use. IMNM is characterized by: proximal muscle weakness and elevated serum creatine kinase, which persist despite discontinuation of statin treatment, positive anti-HMG CoA reductase antibody, muscle biopsy showing necrotizing myopathy and improvement with immunosuppressive agents ( 5.2 ). Liver enzyme abnormalities: persistent elevations in hepatic transaminases can occur. Check liver enzyme tests before initiating therapy and as clinically indicated thereafter. ( 5.3 )
5.1 Skeletal Muscle Rare cases of rhabdomyolysis with acute renal failure secondary to myoglobinuria have been reported with pravastatin and other drugs in this class. A history of renal impairment may be a risk factor for the development of rhabdomyolysis. Such patients merit closer monitoring for skeletal muscle effects. Uncomplicated myalgia has also been reported in pravastatin-treated patients [see Adverse Reactions (6) ]. Myopathy, defined as muscle aching or muscle weakness in conjunction with increases in creatine phosphokinase (CPK) values to greater than 10 times the ULN, was rare (<0.1%) in pravastatin clinical trials. Myopathy should be considered in any patient with diffuse myalgias, muscle tenderness or weakness, and/or marked elevation of CPK. Predisposing factors include advanced age (65), uncontrolled hypothyroidism, and renal impairment. All patients should be advised to promptly report to their physician unexplained muscle pain, tendernes... [See full FDA label]
