Comparing Side Effects of Two Forms of Videx in HIV-Infected Adults

Inclusion Criteria Patients may be eligible for this study if they: Are HIV-positive. Are at least 16 years old (consent of parent or guardian required if under 18). Are taking a stable Videx-containing anti-HIV regimen, using Videx tablets either once or twice a day, for at least 2 weeks prior to the screening visit. Score 2 or higher on the GSRS questionnaire for 1 or more of the following symptoms at the first 2 study visits: abdominal pain, nausea and vomiting, borborygmus, abdominal distension, and loose stools. Agree to use an effective barrier method of birth control during the study. Are available for at least 8 weeks. Exclusion Criteria Patients will not be eligible for this study if they: Are pregnant or breast-feeding. Are taking Videx in liquid form, nelfinavir, or amprenavir. Have a history of pancreatitis or gallstones. Abuse alcohol or require drugs which, in the opinion of the investigator, may increase the risk of pancreatitis. Have had treatment for an active opportunistic (AIDS-related) infection within 4 weeks of the screening visit. Patients with chronic candidiasis (yeast infection) or bacterial infection will be allowed. Are receiving or plan to receive chemotherapy for cancer. Plan to change their medications within 8 weeks following the screening visit. Are receiving investigational drugs or are participating in a clinical trial involving anti-HIV medications. Patients in Phase IV studies (studies that evaluate the long-term safety and effectiveness of a drug, usually after the drug has been approved by the FDA) may be eligible. Have an active, ongoing gastrointestinal disease or infection such as colitis, diverticulitis, Crohn's disease, peptic ulcer disease, giardiasis, or cryptosporidiosis. Are unable to take medications by mouth. Have severe diarrhea. Have peripheral neuropathy (a condition affecting the nervous system) or other condition or prior therapy that, in the opinion of the investigator, would affect the study.