A user may experience some negative side effects from Viramune. The most common serious side effects that can be encountered are these: fevers, throat irritation, signs of liver failure, signs of a new infection, or headaches that are accompanied by a blistering or peeling skin rash. Other, milder adverse reactions may include headaches, nausea, fatigue, abdominal pain, vomiting, or abrupt changes in the location or shape of a person's body fat. In addition, an allergic reaction can be serious and a patient will experience the following symptoms during this type of reaction: muscle and joint pain, pronounced tingling, mouth sores, breathing impairment, facial swelling, weakness of the muscles, and skin rashes. These symptoms should be reported to a local doctor as soon as possible.