Sulfadiazine crystalluria revisited. The treatment of Toxoplasma encephalitis in patients with acquired immunodeficiency syndrome.

Toxoplasma gondii encephalitis is an important opportunistic infection in the acquired immunodeficiency syndrome, estimated to occur in 20,000 to 40,000 patients with acquired immunodeficiency syndrome in the United States by 1991. The combination of sulfadiazine and pyrimethamine is regarded as the treatment of choice. Acute renal failure due to crystal deposition in the urinary tract was well described 30 to 40 years ago and is likely to resurface as a clinical entity if appropriate prophylactic measures are not taken. We describe two cases of sulfadiazine-induced crystalluria and renal failure in patients with acquired immunodeficiency syndrome, review the pertinent literature, and discuss the pathogenesis. Recommendations are made for the prophylaxis and treatment of sulfadiazine-related renal toxic reaction. Physicians using this "new" drug must be aware of the potential danger of sulfonamide-induced injury to the urinary tract.