A Phase I Study to Evaluate the Safety and Toxicity of the Combination of Zidovudine and 2',3'-Dideoxyinosine (Didanosine) in Children With HIV Infection

Inclusion Criteria Concurrent Medication: Allowed: * Corticosteroids for treatment of lymphocytic interstitial pneumonitis. Concurrent Treatment: Allowed: * Intravenous hyperalimentation. Patients must have the following: * P-2 class symptomatic HIV infection as defined by CDC OR who are asymptomatic but whose total CD4 cell count is \< 500 cells/mm3. * Freedom from significant active opportunistic or other infection requiring specific therapy. Part B patients: * Prior treatment with zidovudine (AZT) that was discontinued because of hematologic toxicity. * Availability of a parent or legal guardian who is sufficiently reliable to give informed consent and follow necessary study procedures including administration of medications and return for follow-up visits. Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Critically ill, clinically unstable, or receiving drug therapy for an opportunistic or other infection. * History of acute or chronic pancreatitis. Patients with the following are excluded: * Critically ill, clinically unstable, or receiving drug therapy for an opportunistic or other infection. * History of acute or chronic pancreatitis. Prior Medication: Excluded: * Antiretroviral or other antiviral agent within 14 days of entry into study. * Immunomodulating agents, cytolytic chemotherapeutic agents, corticosteroids within 30 days (except for lymphocytic interstitial pneumonitis). Part A patients: * Zidovudine (AZT) or didanosine (ddI). Part B patients: * Didanosine (ddI). Prior Treatment: Excluded: * Radiation therapy within 30 days. * Intravenous immunoglobulin preparations within 14 days of entry into study.