[Acute renal failure due to non-traumatic rhabdomyolysis in a cocaine addict].

Nontraumatic rhabdomyolysis in drug abusers is well-known, with cocaine and parenteral heroin the most frequent causative agents. Rhabdomyolysis is thought to result from compromised vascular supply to dependent muscles, due to prolonged pressure during long periods of depressed consciousness and immobility. However, recent work in rats has shown marked vasodilatation in areas of injured muscle, mediated by the nitric oxide pathway. Acute renal failure occurs in about 2/3 of the cases of cocaine-associated rhabdomyolysis. The usual clinical picture is that of a mentally obtunded drug addict presenting with swelling and tenderness of the muscles of a limb. However, these findings may be absent or overlooked. Characteristic laboratory features include elevated serum creatinine phosphokinase (CPK) (in excess of 90,000 IU/L) and myoglobinuria. We present a 33-year-old male addict who developed acute renal failure due to cocaine- and heroin-associated rhabdomyolysis. He had marked edema and tenderness of his right leg and was initially erroneously diagnosed as suffering from deep venous thrombosis. Only when the CPK was found to be 47,300 U/L, was the correct diagnosis made. Massive fluid replacement and alkalinization of the urine resulted in rapid improvement in renal function.