RESUMO
A 17-year-old male with uneventful previous history developed generalized myalgias, exercise intolerance, and general fatigue after two dosages of azithromycin (500 mg/d) during 3 d for febrile infection. Neurologic exam revealed generally reduced tendon reflexes. Serum creatine kinase (CK) was elevated to 25000 U/L. Needle-EMG showed short and small, polyphasic motor-units and abnormal spontaneous activity, being interpreted as myositis. Azithromycin was discontinued and he was advised to avoid the fitness studio and to drink plenty of liquids. Myalgias disappeared within two days and CK continuously declined. Azithromycin may trigger rhabdomyolysis in the context of exercise and infection. Azithromycin may be myotoxic and should be prescribed with caution in exercising and infected patients.