Treatment of Pneumocystis carinii pneumonia in adults with AIDS.

Trimethoprim-sulfamethoxazole remains the treatment of choice in patients with Pneumocystis carinii pneumonia (PCP) requiring intravenous therapy. Those patients who require intravenous therapy who cannot tolerate or who fall therapy with trimethoprim-sulfamethoxazole may be treated with either pentamidine or trimetrexate (plus folinic acid), with or without orally administered dapsone. The toxicity of the former drug makes trimetrexate-based therapy the preferred second choice for parenteral use. Treatment with trimethoprim-sulfamethoxazole, dapsone-trimethoprim, or clindamycin-primaquine is approximately of equivalent efficacy, but variable toxicity, in patients with mild to moderate PCP for whom an oral route of administration is appropriate. Atovaquone, formulated as an oral suspension, is also effective, but, in the absence of additional data, must be considered as second line therapy. Adjunctive corticosteroid therapy is indicated for patients with [PAO2-PaO2] more than 30 mm Hg or PaO2 less than 70 mm Hg [corrected] while breathing ambient air in the absence of contraindications. Recognition of the apparent fungal nature of P carinii as well as improved understanding of the pathophysiology of PCP will lead to further improvements in antipneumocystis therapy.