A Phase II, Randomized Study of the Antiviral Activity and Resistance Interactions of Lamivudine (3TC) in Combination With Zidovudine (AZT), Stavudine (d4T), or Didanosine (ddI) Versus Monotherapy With ddI or d4T in HIV-Infected Individuals With 200 - 600 CD4+ Cells/mm3 and No Previous Nucleoside Experience

Inclusion Criteria Concurrent Medication: Allowed: PCP prophylaxis. Patients must have: HIV infection. CD4 count 200 - 600 cells/mm3. Life expectancy of at least 24 weeks. Consent of parent or guardian if less than 18 years old. Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: Unexplained temperature >= 38.5 C for 7 consecutive days within 30 days prior to study entry. PER AMENDMENT 1/25/96: A malignancy that requires systemic chemotherapies other than Kaposi's sarcoma. Concurrent Medication: Excluded: Concurrent other antiretroviral or immunologic agents. Other experimental therapies. Systemic corticosteroids (except as adjuvant therapy for acute PCP) and other immunosuppressive drugs. Systemic cytotoxic chemotherapy. Induction or maintenance with foscarnet or ganciclovir (oral or IV). Patients with the following prior conditions are excluded: History of acute or chronic pancreatitis. History of grade 2 or higher peripheral neuropathy. Prior Medication: Excluded: Antiretrovirals within 90 days prior to study entry. More than 7 days total lifetime use of any antiretroviral nucleoside.