[Rhabdomyolysis in antiretroviral therapy with Lamivudin]

Six weeks after antiretroviral treatment with lamivudin (a nucleoside analogue) had been started (300 mg daily) in a 31-year-old man with AIDS developed pain and weakness in his muscles. On admission he had myalgia on pressure and movement as well as weakness of the entire body musculature, especially of the arms. The history and findings suggested bacterial or HIV-associated myositis.

Creatinekinase activity (4442 U/l) and myoglobin concentration (3250 micrograms/l) were greatly increased, while creatine (96 mumol/l) and C-reactive protein (22 mg/l) levels were only slightly raised. Serology was negative for acute and bacterial infections and autoimmune myositis. Magnetic resonance imaging and biopsy indicated marked rhabdomyolysis without myositis.

After excluding other causes, lamivudin and other drugs were discontinued, drug-induced rhabdomyolysis being suspected. This and the administration of prednisolone (100 mg daily) improved the symptoms. Creatinekinase activity and myoglobin level became normal within 14 days. On renewed administration of lamivudin creatinekinase and myoglobin concentrations in serum doubled to 180 U/l and 110 micrograms/l, respectively. Cessation of medication once again restored them to normal.

Rhabdomyolysis is a serious but rare side effect of lamivudin treatment. Appropriate biochemical monitoring should therefore be undertaken when it is used in the treatment of HIV-positive patients.