Ombitasvir is used as an antiviral agent in the treatment of chronic hepatitis C virus (HCV) infection. It functions as an NS5A inhibitor, blocking a key viral protein required for replication and assembly of HCV. It is typically administered in combination with other antivirals such as paritaprevir and ritonavir, often with dasabuvir, to increase efficacy and reduce the risk of resistance. This combination therapy is effective across multiple HCV genotypes, particularly genotype 1 and 4. Ombitasvir-based regimens offer high cure rates, shorter treatment duration, and fewer side effects compared to older interferon-based therapies. It is used in patients with compensated liver disease, including those with cirrhosis, and has played a significant role in improving outcomes in HCV management.