A Randomized, Comparative Study of Daily Dapsone and Daily Atovaquone for Prophylaxis Against PCP in HIV-Infected Patients Who Are Intolerant of Trimethoprim and/or Sulfonamides

Inclusion Criteria Concurrent Medication: Strongly recommended: * Pyrimethamine (50 mg) and folinic acid (15 mg) weekly in patients receiving dapsone who have CD4 count \< 100 cells/mm3 and are toxoplasmosis seropositive. Patients must have: * Working diagnosis of HIV infection. * CD4 count \<= 200 cells/mm3 or \<= 15 percent of total lymphocyte count at any time in the past OR a history of PCP. * History of intolerance of trimethoprim and/or sulfonamides that required permanent discontinuation. NOTE: * Pregnant patients are eligible at the clinician's discretion. Prior Medication: Allowed: * Prior PCP prophylaxis. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: * Active pneumocystosis. Concurrent Medication: Excluded: * PCP prophylaxis (other than study drug) or any medication with potential anti-PCP activity. Patients with the following prior conditions are excluded: * Known treatment-limiting reaction to dapsone or atovaquone.