Eflornithine Treatment of Refractory Pneumocystis carinii Pneumonia in Patients with Acquired Immunodeficiency Syndrome

Abstract

Eflornithine was offered as compassionate treatment of 33 episodes of Pneumocystis carinii pneumonia in 31 patients with acquired immunodeficiency syndrome who were intolerant of and/or unresponsive to conventional trimethoprim-sulfamethoxazole or pentamidine therapy. A full course of eflornithine consisted of ten days at 400 mg/kg/d but no more than 30 g/d in four divided intravenous doses, four days at 300 mg/kg/d in four divided intravenous doses, and then up to six weeks at 300 mg/kg/d in four divided oral doses where tolerated. Of 33 patient-episodes, 15 patients were discharged from the hospital without need for supplemental oxygen after receiving ten or more days of parenteral therapy and were classified as responders. Of the 16 episodes classified as treatment failures, death occurred within the first 10 days of therapy in 12, and supplemental oxygen could not be withdrawn in 4. The other two patients left the hospital without need of oxygen after receiving one and six days of treatment with eflornithine and were not considered evaluable for efficacy. The most serious adverse effect was thrombocytopenia, which occurred in 12 of 19 patients treated for ten days or more. Serious bleeding associated with thrombocytopenia was observed in two patients. Other common adverse effects were anorexia, nausea, and diarrhea. Prior to receiving eflornithine, 13 of 15 responders had received ten or more days of conventional therapy without demonstrating clinical improvement. Two had improved while receiving conventional therapy but were switched to eflornithine because of a treatment-limiting adverse effect of standard therapy. These results suggest that eflornithine may be useful as an alternative therapeutic agent for Pneumocystis carinii pneumonia. Studies designed to determine proper dosage, duration of therapy, and efficacy as primary therapy are warranted.