Observational Study With Antiretroviral Treated Patients Switching to Nevirapine Plus Two Nucleoside Reverse Transcriptase Inhibitor (NRTI) Regimens

Inclusion Criteria: * Patients suffer from HIV type 1 infection * Patient is treated with antiretroviral protease-inhibitors or non-nucleoside reverse transcriptase inhibitors * Patient has shown a depression of viral load before limit of detection (\< 50 HIV-RNA copies/ml) for more than 6 months prior to visit 1 * Patient is male or female with age greater than or equal to 18 years * Women have to be willing to use an effective barrier method of contraception for the duration of the observational study participation Exclusion Criteria: * Patient has clinically relevant laboratory findings (e.g., aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \> five times upper limit of normal (ULN)) * Patients is hypersensitive to Viramune® or to any of its excipients * Patient is not able to abstain from treatment with ketoconazole, oral contraceptives, or other drug affecting CYP3A-metabolism * Patients is breast-feeding * Patient is pregnant * Patient is a woman and does not use effective contraception