Previous tests have shown that SMX/TMP given daily is effective in preventing recurrence of PCP and may be effective in preventing PCP in patients who have never developed it. Because SMX/TMP can cause side effects, this study will attempt to determine the safest and most effective dose of this combination.~Patients receive SMX/TMP orally on a daily or thrice-weekly basis. Patients are clinically evaluated every 4 months. Patients on daily SMX/TMP who develop a drug-related toxicity may be switched to thrice-weekly SMX/TMP. Duration of follow-up is 12 months.
To compare the safety and efficacy of two dosage regimens (daily and thrice-weekly) of sulfamethoxazole/trimethoprim (SMX/TMP; TMS) in the prevention of Pneumocystis carinii pneumonia (PCP) in high-risk HIV-infected patients.~Previous tests have shown that SMX/TMP given daily is effective in preventing recurrence of PCP and may be effective in preventing PCP in patients who have never developed it. Because SMX/TMP can cause side effects, this study will attempt to determine the safest and most effective dose of this combination.