A Double-Blind, Randomized Parallel Group Study Comparing Procysteine to Placebo in HIV-Infected Patients Who Are Taking Antiretroviral Nucleosides

Inclusion Criteria Concurrent Medication: Required: Antiretroviral nucleosides (AZT alone, ddI alone, AZT plus ddI, or AZT plus ddC). Regimen may be altered on or after Week 16. Allowed: Appropriate topical treatment or local radiotherapy for KS. Treatment or prophylaxis for opportunistic infections, including pentamidine, cotrimoxazole, acyclovir, fluconazole, etc., at the discretion of the investigator. Patients must have: Documented serologic evidence confirming HIV infection. Ability to participate in an outpatient study for at least 26 weeks. Either: (a) diagnosis of AIDS or AIDS-Related Complex (ARC) with CD4 count of 50 - 300 cells/mm3, or (b) CD4 count of 50 - 200 cells/mm3 and no symptoms of AIDS (asymptomatic). (Note: Patients whose AIDS-defining condition is Kaposi's sarcoma alone must have CD4 count of 50 - 200 cells/mm3.) Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: Evidence of organ involvement with CMV and/or positive blood cultures for Mycobacterium avium. Life expectancy less than 26 weeks. Malignancy or advancing Kaposi's sarcoma (KS) with advancing or unstable skin lesion, or known or suspected visceral disease which requires systemic cytotoxic, myelosuppressive chemotherapy. Stage 2 or greater AIDS-dementia complex (ADC), defined as ability to perform basic activities of self-care but inability to work or maintain more demanding aspects of daily life as a result of an acquired decrease in cognitive CNS-related motor function characteristic of ADC. Psychological or emotional problems that prevent adequate compliance with study therapy. Concurrent Medication: Excluded: Daily Vitamin C dosage greater than 1,000 mg or daily Vitamin E dosage greater than 100 units. N-acetylcysteine, cysteine, or glutathione. Any investigational drug. Systemic chemotherapy. Patients with the following prior conditions are excluded: History of organ involvement with cytomegalovirus (CMV) and/or positive blood cultures for Mycobacterium avium. Intractable diarrhea, defined as greater than 4 bowel movements per day for at least 2 weeks. History of seizures which have not been controlled with appropriate anticonvulsant medications within the previous 6 months. Prior Medication: Excluded: Any investigational agent or biological response modifier (including interferon or corticosteroids) within 1 month of study entry. Use of erythropoietin (EPO), G-CSF, or GM-CSF within 28 days of randomization. Risk Behavior: Excluded: Active alcohol or drug abuse. Required: Antiretroviral nucleosides (AZT alone, ddI alone, AZT plus ddI, or AZT plus ddC) for at least 3 months prior to study entry.