Sofosbuviiri

Sofosbuviiri, or sofosbuvir, is a nucleotide analogue antiviral used to treat chronic hepatitis C virus infection. It is a prodrug that is metabolized in the liver to an active triphosphate form, which inhibits the HCV NS5B RNA-dependent RNA polymerase and thereby blocks viral RNA synthesis. Sofosbuvir has activity against multiple HCV genotypes and is a central component of interferon-free direct-acting antiviral regimens.

It is used in adults and select paediatric patients as part of combination therapy with other direct-acting antivirals. Common fixed-dose combinations include sofosbuvir/ledipasvir (Harvoni) and sofosbuvir/velpatasvir (Epclusa). Treatment duration is typically 8 to 12 weeks, depending on genotype, cirrhosis status, and prior treatment history.

The usual dose is 400 mg once daily, taken with or without food. It is not given alone but in combination regimens, sometimes with ribavirin in certain situations.

Sofosbuvir is generally well tolerated. Common adverse effects include fatigue, headache and nausea; anemia may occur when combined with ribavirin. Rare but serious concerns include bradycardia when used with amiodarone and liver-related events in patients with advanced cirrhosis. Drug interactions exist, particularly with P-glycoprotein inducers or inhibitors; patients should review concomitant medicines with a clinician.

Sofosbuvir was developed by Gilead Sciences and approved for HCV treatment in 2013. It is marketed worldwide in fixed-dose combinations, with generic versions available in many regions.