The purpose of this study is to test the safety and effectiveness of a new non-nucleoside reverse transcriptase inhibitor (NNRTI), (+)-calanolide A, in HIV-positive patients who have never received anti-HIV treatment.

Patients are randomized into 2 cohorts, with Cohort 2 receiving a higher dosage than Cohort 1. Patients in each cohort receive either (+)-calanolide A or a placebo for 14 days, followed by a 14-day follow-up period. Following study treatment, patients may elect to receive an open-label, 6-month course of anti-HIV drugs to be selected by and administered under the care of the patient's physician.

Inclusion Criteria

You may be eligible for this study if you:

• Are HIV-positive.
• Have a CD4 count of at least 250 cells/mm3.
• Have an HIV count (viral load) of at least 5,000 copies/ml.
• Are at least 18 years old.

Exclusion Criteria

You will not be eligible for this study if you:

• Have received prescription or nonprescription medications within 14 days of study entry, or if you will need to take any of these medications during the study.
• Have ever received anti-HIV medications.
• Test positive for hepatitis B.
• Have received a blood (or red blood cell) transfusion within 3 months prior to study entry.
• Have severe diarrhea.
• Have severe heart, liver, kidney, or neurological (brain and spinal cord) disease.
• Have hemophilia or another blood disorder.
• Have received certain medications or vaccines within 30 days prior to study entry.
• Have received chemotherapy or radiation within 16 days prior to study entry, or if you will need either of these during the study.