Dapsone-trimethoprim for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

All patients with the acquired immunodeficiency syndrome and a first episode of Pneumocystis carinii pneumonia seen at the San Francisco General Hospital between November 1984 and April 1985 were evaluated for oral treatment with dapsone (100 mg/d) plus trimethoprim (20 mg/kg body weight X d). All 15 patients who met the entry criteria improved clinically and radiographically within 3 to 10 days after starting treatment. Repeat pulmonary function tests and gallium lung scans after 3 weeks of therapy also showed improvement. Although side effects occurred in 14 patients, in only 2 were they severe enough to require stopping therapy. Both of these patients had worsening skin rash, and dapsone-trimethoprim therapy was stopped after 10 days. When compared with trimethoprim-sulfamethoxazole or pentamidine used to treat P. carinii pneumonia in similar patients, oral dapsone-trimethoprim is at least as effective, seems to be better tolerated, and may have a lower frequency of serious side effects.