Abstract

ABSTRACT: The increased resistance, intolerance, or allergy to trimethoprim/sulfamethoxazole (TMP/SMX) has brought much attention to alternative treatment of pneumonia caused by Pneumocystis carinii (PCP). Pentamidine is considered when there is documented allergy or intolerance to TMP/SMX. Similarly, either dapsone/trimethoprim or clindamycin/primaquine is effective in the treatment of mild to moderate PCP, but both regimens are contraindicated in glucose 6-phosphate dehydrogenase (G6PD) deficiency. For this purpose, atovaquone should be used in patients who are deficient in G6PD or who are unable to be on TMP/SMX or pentamidine. On the other hand, in severe disease, adjunctive corticosteroids can enhance the efficacy of either TMP/SMX or pentamidine. If these therapies yield no response, trimetrexate with leucovorin has been approved as initial and salvage therapy in severe PCP. We review alternative treatment to TMP/SMX and propose ideal and practical therapeutic and prophylactic guidelines in the treatment and prevention of PCP.