A Phase I Safety and Pharmacokinetics Study of 2',3'-Dideoxyinosine (ddI) Administered Twice Daily to Infants and Children With AIDS or Symptomatic HIV Infection

Inclusion Criteria Concurrent Medication: Allowed: * Aerosolized pentamidine for Pneumocystis carinii pneumonia (PCP) prophylaxis if this drug is extended to children. * Acute therapy not exceeding 7 days with oral or intravenous acyclovir for herpes simplex infections. * Trimethoprim / sulfamethoxazole for Pneumocystis carinii infections during course of study at discretion of investigator after discussion with the sponsor. * Symptomatic therapy with analgesics, antihistamines, antiemetics, antidiarrheal agents, or other supportive therapy as deemed necessary by the principal investigator. Patients must have: * Diagnosis of AIDS as defined by CDC or meeting CDC P2 classification. * Patients must be free of opportunistic infection or other serious bacterial, fungal, or parasitic infection at time of entry into study. * Life expectancy \> 6 months. * Parent or guardian (and patient as applicable) able to give informed consent. * Available for follow-up for at least 6 months. * Allowed: Hemophilia. Exclusion Criteria Co-existing Condition: Children with the following are excluded: * Chronic hematologic disorders unrelated to coagulation defects, hemoglobinopathies, or ITP. * Intractable diarrhea. * No venous access. * History of seizures within previous 2 years or currently requiring anticonvulsants for control. * Currently active heart disease as evidenced by a cardiac arrhythmia or other significant abnormality on routine electrocardiography (ECG) or shortening fraction of \< 10 percent on echocardiogram. * Renal disease. * Any other clinical condition that in the opinion of the investigator makes the patient unsuitable for study. Concurrent Medication: Excluded: * Antiretroviral drugs. * Zidovudine (AZT). * AL 721. * Interferon. * Corticosteroids. * Immunomodulating drugs. * Other systemic investigation agent. * Ribavirin. * Rifampin, barbiturates, or any other potent inducer or inhibitor of drug-metabolizing enzymes. * Cytotoxic anticancer therapy. * H-2 blockers. * Intravenous ketoconazole. * Immunoglobulin preparations. Children with the following are excluded: * Chronic hematologic disorders unrelated to coagulation defects, hemoglobinopathies, or ITP. * Intractable diarrhea. * No venous access. * History of seizures within previous 2 years or currently requiring anticonvulsants for control. * Currently active heart disease as evidenced by a cardiac arrhythmia or other significant abnormality on routine electrocardiography (ECG) or shortening fraction of \< 10 percent on echocardiogram. * Renal disease. * Any other clinical condition that in the opinion of the investigator makes the patient unsuitable for study. * Renal disease. Prior Medication: Excluded: * Any prior therapy which in the opinion of the investigator would make the patient unsuitable for study. Excluded within 2 weeks of study entry: * Trimethoprim / sulfamethoxazole. Excluded within 1 month of study entry: * Study drug or other antiretroviral drug or systemic investigational agent. * Any agent known as a potent inducer or inhibitor of drug metabolizing enzymes. * H-2 blockers. * Ketoconazole. * Immunoglobulin preparations. Excluded within 3 months of study entry: * Ribavirin. Excluded: * Zidovudine (AZT) for \> 6 months. * Cytotoxic anticancer therapy. Prior Treatment: Excluded within 4 weeks of study entry: * Blood transfusion. * Lymphocyte transfusions for immune reconstitution. * Bone marrow transplant.