To the Editor.
—In the August 1987 issue of the Archives, Kales et al1 analyzed clinical and laboratory data in 145 patients with Pneumocystis carinii pneumonia (PCP). They identified the following variables that were associated with increased in-hospital mortality: multiple admissions, leukocytosis, elevated lactic dehydrogenase levels, decreased oxygen pressure (tension) and carbon dioxide (tension), decreased serum albumin levels, and concurrent pulmonary infections. Patients with normal respiratory rates and normal chest examinations had increased survival rates.The authors fail to indicate the drugs that were used to treat the patients. Sulfamethoxazole and trimethoprim and pentamidine are both effective in treating PCP. However, the use of sulfamethoxazole and trimethoprim should be avoided in patients with a history of allergy to its components or patients who require fluid restriction, since intravenous administration requires at least 1200 mL of fluid daily. Sulfamethoxazole and trimethoprim is the drug of choice in patients with preexisting