Inclusion Criteria

Concurrent Medication:

Allowed:

• Zidovudine (AZT), didanosine (ddI), dideoxycytidine (ddC), erythropoietin (Eprex), other agents granted Treatment IND or expanded access status.
• Investigational triazoles.
• Pentamidine for primary prophylaxis of Pneumocystis carinii pneumonia (PCP).

Patients with the following are excluded:

• History of cerebral toxoplasmosis or toxoplasmosis infection in any other organ or tissue.
• Focal neural abnormalities (except peripheral neuropathy) or mass lesions on a previous computerized tomography (CT) scan or magnetic resonance image (MRI), unless subsequent workup rules out toxoplasmosis, in which case abnormalities must have been stable for at least 2 months.
• Known or suspected allergy or severe intolerance to study drugs.

Patients must have:

• Positive toxoplasma serology.
• HIV infection.
• Willingness and ability to comply with the protocol and capability of giving written informed consent.

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded:

• Current diagnosis of cerebral toxoplasmosis or toxoplasmosis infection in any other organ or tissue.
• Known or suspected allergy or severe intolerance to study drugs.

Concurrent Medication:

Excluded:

• Anticoagulants. Other antifolates, sulfonamides, fansidar, macrolides, 5-fluorouracil, dapsone, or any other agent with known activity against Toxoplasma gondii.