An Open-Label Study in HIV+ Patients to Determine the Effects of Nevirapine (Viramune) on the Pharmacokinetics of Clarithromycin and Activity of Cytochrome 3A4.

Inclusion Criteria Concurrent Medication: Allowed: Antiretroviral drugs (i.e., zidovudine, zalcitabine, stavudine, lamivudine, didanosine, indinavir, saquinavir) provided that there has been no change in dosing of the medication \> 25% within 4 weeks of study entry. Patients must have: * HIV positive status. * CD4 count \>= 100 cells/mm3. Prior Medication: Allowed: Patients may be on clarithromycin at study entry. Exclusion Criteria Co-existing Condition: Patients with the following conditions are excluded: Malabsorption, severe chronic diarrhea, or inability to maintain adequate oral intake. Concurrent Medication: Excluded: Macrolide antibiotics (erythromycin, azithromycin, dirithromycin), azole fungals (ketoconazole, fluconazole, itraconazole), rifampin, rifabutin, phenytoin, terfenadine, astemizole, cisapride, triazolam, midazolam, other non-nucleoside reverse transcriptase inhibitors, antibiotics containing clavulanic acid, and Augmentin. Patients with the following prior conditions are excluded: * History of drug allergy or known drug hypersensitivity. * History of clinically important disease including hepatic, renal, cardiovascular, or gastrointestinal disease. Prior Medication: Excluded: * Investigational drugs or antineoplastic agents within 12 weeks of study entry. * Participation in a clinical trial that used ERMBY within one year of study entry. * Systemic treatment with drugs known to be potent hepatic enzyme inducers or inhibitors (e.g., oral macrolide antibiotics, azole antifungals, cimetidine, rifampin, rifabutin, and carbamazepine) within 28 days of study entry. * Use of protease inhibitors; ritonavir, nelfinavir, indinavir, or non-nucleoside reverse transcriptase inhibitor compounds e.g., delavirdine) within 4 weeks of study entry. Prior Treatment: Excluded: Radiotherapy within 12 weeks of study entry. Risk Behavior: Excluded: Current history (within the last year) of IVDA, ETOH, or substance abuse.