A Randomized Prospective Study of Pyrimethamine Therapy for Prevention of Toxoplasmic Encephalitis in HIV-Infected Individuals With Serologic Evidence of Latent Toxoplasma Gondii Infection

Inclusion Criteria

Concurrent Medication:

Required:

• Prophylactic treatment for Pneumocystis carinii pneumonia with aerosolized pentamidine, dapsone, or trimethoprim / sulfamethoxazole.

Allowed:

• Most medications not specifically excluded.

Prior Medication:

Allowed:

• Antivirals.
• Antiretrovirals.

Patients:

• Must be HIV positive or have an AIDS-defining illness OR be at known risk for HIV infection and have a CD4 cell count < 200/mm3 and no other known immunosuppressive disease.
• Must have positive titer for Toxoplasma gondii.
• Must be or become a patient of a CPCRA physician.
• May participate in other clinical trials as long as there is no potential activity against Toxoplasma gondii or cross-toxicity among study drugs.

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded:

• History of ocular, pulmonary, or central nervous system (CNS) toxicity.
• CNS lesions.
• Neurologic deficits except peripheral neuropathy.
• Mild, moderate, severe, or end-stage AIDS dementia complex. Grade 3 or higher nausea and/or vomiting.
• Sensitivity to pyrimethamine.

Concurrent Medication:

Excluded:

• On-going therapy with clindamycin, fansidar, methotrexate, trimetrexate, spiramycin, azithromycin, clarithromycin, 566C80, and/or sulfa agents other than anti-PCP agents.

Patients with the following are excluded:

• History of ocular, pulmonary, or central nervous system (CNS) toxicity.
• CNS lesions or history of CNS lesions.
• Neurologic deficits except peripheral neuropathy.
• Mild, moderate, severe, or end-stage AIDS dementia complex. Grade 3 or higher nausea and/or vomiting.
• Sensitivity to pyrimethamine.

History of severe allergic reactions to study medication Currently pregnant or breastfeeding Recent participation in another clinical trial within the last 30 days Presence of uncontrolled medical conditions that could affect safety