The primary purpose of this study is to determine if dronabinol is effective in preventing or treating nausea caused by HAART (highly active anti-retroviral therapy) in HIV and AIDS patients

Inclusion Criteria:

• Adherence to prior or current HAART was or is being compromised, or HAART was discontinued/interrupted due to nausea/vomiting; or beginning HAART or switching from a regimen at the time of screening for this study that did not produce significant nausea and/or vomiting to a regimen with zidovudine or a protease inhibitor (with or without low dose ritonavir).

Exclusion Criteria:

• Subjects with recent (within 30 days of randomization) or current opportunistic infection or neoplasm characteristic of AIDS (Category C of the CDC Classification System for HIV-1 infection, 1993 Revised Version).