Daclatasvir is an antiviral medication used to treat infections caused by the hepatitis C virus (HCV). It works by inhibiting a specific protein that the virus needs to replicate, helping to reduce the amount of virus in the body. Daclatasvir is often used in combination with other antiviral drugs to enhance its effectiveness. This medication is typically taken orally, and the treatment duration can vary depending on the specific strain of HCV and the patient's health. Common side effects may include fatigue, headache, and nausea. Regular monitoring by a healthcare provider is essential during treatment to ensure safety and effectiveness.