Inclusion Criteria

Concurrent Medication:

Allowed:

• Acyclovir (if patient is also receiving ddC, clinical monitoring should be more frequent).
• Analgesics, antiemetics, antidiarrheal agents, or other necessary treatment for symptomatic therapy.
• Interferons for maintenance therapy of Kaposi's sarcoma.
• GM-CSF.

Required:

• Prophylaxis against Pneumocystis carinii pneumonia (PCP) if their absolute CD4+ lymphocyte count is < 200 cells/mm3 at study entry. PCP prophylaxis for patient with CD4+ counts between 200 and 300 cells/mm3 is at discretion of patient's primary physician.
• NOTE: There is potential interaction of ddI and dapsone.

Concurrent Treatment:

Allowed:

• Transfusion, erythropoietin.

Patients must have the following:

• Zidovudine (AZT) failure after having received a cumulative duration of at least 6 months.
• AZT intolerance - rechallenge is not required for patients exhibiting = or > grade III cutaneous symptoms.
• Diagnosis of AIDS or CD4+ = or < 300 cells/mm3 OR AIDS-defining illness other than Kaposi's sarcoma.
• Willingness and ability to comply with protocol.
• Informed consent must be obtained for all study participants in accordance with state law, local IRB requirements, and 45 CFR Part 46. AMENDED 11/19/90 to include assent by minors if they are physically able, in addition to consent by parents.

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded:

• Any disorders for which the study drugs are contraindicated (didanosine (ddI)) is contraindicated in renal impairment, heart disease, receiving renal dialysis.
• Active opportunistic infection.

Concurrent Medication:

Excluded:

• Other antiretroviral agents.
• Use of drugs associated with peripheral neuropathy or use of agents that may cause pancreatitis including intravenous pentamidine and alcohol should be restricted or avoided.

Concurrent Treatment:

Excluded:

• Other concurrent antiretroviral clinical trials.

Patients with the following are excluded:

• History of pancreatitis, peripheral neuropathy, uncontrolled seizures, renal impairment, heart disease, stage 2 or higher ADC.
• Any other disorders for which the study drugs are contraindicated, i.e., ddI is contraindicated in renal impairment, patients receiving renal dialysis, and heart disease.
• Receiving acute therapy for active AIDS defining opportunistic infection on enrollment.

Prior Medication:

Excluded:

• Didanosine (ddI).
• Dideoxycytidine (ddC) .

Excessive alcohol use that, in investigator's opinion, puts patient at risk of developing pancreatic disease.