Pravastatin-Associated Inflammatory Myopathy

Abstract

It has been reported that lovastatin, a potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, can cause a toxic, noninflammatory myopathy.^{1 , 2} We describe a 66-year-old woman treated for five months with pravastatin (10 mg per day), a HMG-CoA reductase inhibitor different from lovastatin, in whom a syndrome resembling dermatomyositis developed over a period of five weeks. She was admitted with severe subacute proximal-muscle weakness in the upper limbs and had prominent bullous erythematous skin lesions on her face, neck, shoulder, chest, and arms. The serum creatine kinase level was elevated (>4000 U per liter), a muscle biopsy revealed endomysial and perimysial cellular infiltrates ( Fig. 1 A), and an electromyogram showed a myopathic pattern with denervation potentials. A skin biopsy did not reveal eosinophilic cell infiltrates, providing evidence against an allergic reaction. Pravastatin was discontinued, and the patient was given high doses of corticosteroids, which were gradually tapered. This was followed by clinical improvement in her weakness, regression of the skin lesions, and normalization of the ereatine kinase levels. Further investigation did not reveal an underlying neoplasm. No relapse of muscle or skin symptoms has occurred for more than seven months.