Daclatasvir is an antiviral medicine that prevents hepatitis C virus (HCV) from multiplying in your body. Daclatasvir is used in combination with other medications to treat chronic hepatitis C in adults. Daclatasvir treats specific genotypes of hepatitis C, and only in certain people. Daclatasvir is an antiviral medicine that prevents hepatitis C virus (HCV) from multiplying in your body. Daclatasvir is used in combination with other medications to treat chronic hepatitis C in adults. Daclatasvir treats specific genotypes of hepatitis C, and only in certain people.