To evaluate the safety and efficacy of high-dose lamivudine (3TC) alone versus zidovudine (AZT) alone versus 3TC at high and low doses in combination with AZT in HIV-1 infected patients.

PER 02/27/95 AMENDMENT: To evaluate the efficacy and safety of both blinded and open-label combination therapy.

Patients are randomized to one of four treatment arms: 3TC alone, AZT alone, low-dose 3TC plus AZT, or high-dose 3TC plus AZT. Patients receive treatment for 32 weeks, with possible extension to 52 weeks.

PER 02/27/95 AMENDMENT: Patients may continue therapy on AZT and low-dose 3TC on an open-label basis. Open-label therapy continues with follow-up every 8 weeks until intolerable toxicity occurs or study terminates.

Inclusion Criteria

Patients must have:

• HIV positivity.
• CD4 count 200-500 cells/mm3.
• AZT naive status (<= 4 weeks of prior AZT).

Exclusion Criteria

Patients with the following prior condition are excluded:

History of intolerance to AZT.

Prior Medication:

Excluded:

• More than 4 weeks of prior AZT.
• Any prior antiretroviral treatment other than AZT.