Hyponatremia associated with levamisole-adulterated cocaine use in emergency department patients.

An increasing percentage of US cocaine has been adulterated with levamisole, an immunomodulator associated with agranulocytosis. We describe 3 emergency department patients with hyponatremia and cocaine use. Despite extensive evaluation, the cause of the hyponatremia was not elucidated but resolved during hospitalization. Because hyponatremia has not previously been associated with cocaine, we sought to uncover a plausible explanation that might be contributing to this new finding. Levamisole was detected in all 3 patients. Although we are unable to confirm causality, we propose that levamisole-adulterated cocaine may have contributed to the hyponatremia described in these patients.