Nevirapine (NVP), sold under the brand name Viramune among others, is a medication used to treat and prevent HIV/AIDS, specifically HIV-1. It is generally recommended for use with other antiretroviral medications. It may be used to prevent mother to child spread during birth but is not recommended following other exposures. It is taken by mouth. Common side effects include rash, headache, nausea, feeling tired, and liver problems. The liver problems and skin rash may be severe and should be checked for during the first few months of treatment. It appears to be safe for use during pregnancy. It is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and works by blocking the function of reverse transcriptase. Nevirapine was approved for medical use in the United States in 1996. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. Medical uses Nevirapine is used in people six years of age and older infected with HIV-1 as part of combination antiretroviral treatment (ART or cART). Monotherapy with nevirapine is not indicated due to rapid emergence of resistance. Nevirapine in triple combination therapy has been shown to suppress viral load effectively when used as initial antiretroviral therapy (i.e., in antiretroviral-naive patients). Some clinical trials have demonstrated comparable HIV suppression with nevirapine-based regimens to that achieved with regimens based on a protease inhibitor (PI) or efavirenz. This drug is generally only to be considered for use if the CD4 cell count is very low. Although concerns have been raised about nevirapine-based regimens in those starting therapy with high viral load or low CD4 count, some analyses suggest that nevirapine may be effective in this group of people. Nevirapine may also form a useful component of salvage regimens after virological failure, usually in combination with one or more PIs as well as nucleotide reverse transcriptase inhibitor (NRTIs), especially in those who have not previously taken an NNRTI. Dosing in children is based on body surface area (BSA), however, weight-based dosing algorithms have been released. These guidelines include dosing algorithms for as young as newborn babies. Preventing mother-to-child transmission A single dose of nevirapine given to both mother and child reduced the rate of HIV transmission by almost 50% compared with a very short course of zidovudine (AZT) prophylaxis, in a clinical trial in Uganda. A subsequent study in Thailand showed that prophylaxis with single-dose nevirapine in addition to zidovudine