Inclusion Criteria

Concurrent Medication:

Allowed:

• Alternative or additional antiretroviral agents if on a stable dose for 8 weeks prior to study entry.
• Isoniazid.
• Anticonvulsants.
• Benzodiazepines and antidepressants (provided dose is stable prior to study entry).
• Symptomatic therapies (e.g., analgesics, antihistamines, antiemetics, and antidiarrheal agents).
• Maintenance therapy with clarithromycin, azithromycin, amikacin, ethambutol, clofazimine, ciprofloxacin, and rifampin for disseminated Mycobacterium avium infection.
• Maintenance therapy for opportunistic infections (e.g., PCP, MAI, CMV).

Patients must have:

• Documented HIV infection.
• HIV-Associated Motor / Cognitive Complex.
• Acceptable neurological and neuropsychological impairment scores.
• Estimated premorbid IQ of 70 or greater, consistent with completion of the sixth grade or ability to read at the sixth grade level. Current ability to read and comprehend a newspaper or history of such ability will satisfy this criterion for patients whose formal education stopped before the sixth grade. For patients who are illiterate, ability to make change from a dollar for a combined purchase of two items or the history of such ability will satisfy this criterion. In the absence of a functional definition, an age-correlated scaled score of > 5 on the Vocabulary Subtest of the WAIS-R or WISC-R may be used to establish IQ.
• Ability to provide written informed consent.

Prior Medication:

Required:

• AZT for at least 12 weeks prior to study entry or any other approved antiretroviral agent (i.e., ddI or ddC) for at least 8 weeks prior to study entry, except in antiretroviral-intolerant patients who must be off antiretrovirals for at least 4 weeks.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms and conditions are excluded:

• Active symptomatic AIDS-defining opportunistic infection (maintenance therapy for opportunistic infections, e.g., Pneumocystis carinii pneumonia, Mycobacterium avium infection, and cytomegalovirus, is permitted).
• Neoplasms other than basal cell carcinoma, in situ carcinoma of the cervix, or Kaposi's sarcoma without evidence of visceral involvement or that do not require systemic chemotherapy.
• Confounding neurological disorders, including the following:
• a) neurologic disease unrelated to HIV infection (such as multiple sclerosis, documented stroke, degenerative disease); b) chronic seizure disorders or head injuries if the condition results in functional impairment or is likely to interfere with evaluations; c) central nervous system (CNS) infections or neoplasms (such as toxoplasmosis, primary or metastatic CNS lymphoma, progressive multifocal leukoencephalopathy, cryptococcal or other fungal meningitis, tuberculous CNS infections, or untreated neurosyphilis).
• Severe premorbid psychiatric illness including bipolar illness, schizophrenia, and depression requiring electroconvulsive therapy.
• Major depression likely to interfere with evaluation or protocol compliance.

Concurrent Medication:

Excluded:

• Major psychotropic medication, including MAO inhibitors, phenothiazines, butyrophenones, barbiturates, or amphetamines (unless a stable dose is maintained for 30 days prior to study entry).
• Any ongoing maintenance therapy for confounding neurological disorders.

Patients with the following prior conditions are excluded:

Confounding neurological disorders defined in the "Exclusion Co-existing Conditions" field.

Prior Medication:

Excluded:

• Investigative drugs within 30 days prior to study entry.
• Confounding calcium channel antagonists (such as nifedipine, verapamil, diltiazem, and related drugs) within 4 weeks prior to study entry.

Active alcohol or drug abuse.