Inclusion Criteria

Concurrent Medication:

Allowed:

• Zidovudine (AZT).
• Dideoxycytidine (zalcitabine; ddC).
• Didanosine (ddI).
• Nonaminoglycoside, nonmacrolide, and nonsulfonamide antibiotics.
• Factor VIII.
• IVIG.

Patients must have:

• AIDS, documented HIV infection, perinatal exposure to HIV, or risk of developing PCP.
• Normal EKG and chest radiograph.
• No blood or protein on urinalysis.
• Consent of parent or guardian.

Prior Medication:

Allowed:

• Prophylactic TMP/SMX if given no less than 3 days prior to study entry.
• Prophylactic aerosolized pentamidine (or a single intravenous dose of 4.0 mg/kg pentamidine) if given no less than 7 days prior to study entry.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Anticipated organ system or laboratory abnormalities (other than immune system abnormalities) from the primary disease and its treatment during the study.
• Acute or chronic infections requiring treatment during the study. NOTE:
• Thrush and herpes labialis are allowed if these conditions do not require treatment.
• Diarrhea or vomiting.

Concurrent Medication:

Excluded:

• Trimethoprim/sulfamethoxazole.
• Sulfadoxine and pyrimethamine (Fansidar).
• Primaquine.
• Aspirin.
• Amphotericin B.
• Aminoglycoside antibiotics.
• Sulfonamides.
• Dapsone.
• Benzodiazepines.
• Rifampin.
• Erythromycin, clarithromycin, and azithromycin.
• Digitalis.
• Para-aminosalicylic acid (PAS).
• Isoniazid.
• Anticoagulants.
• Any other investigational therapies.

Patients with the following prior condition are excluded:

• History of G6PD deficiency.