Sofosbuvir

Sofosbuvir, sold under the brand name Sovaldi among others, is a medication used to treat hepatitis C. It is taken by mouth.

Common side effects include fatigue, headache, nausea, and trouble sleeping. Side effects are generally more common in interferon-containing regimens. Sofosbuvir may reactivate hepatitis B in those who have been previously infected. In combination with ledipasvir, daclatasvir or simeprevir, it is not recommended with amiodarone due to the risk of an abnormally slow heartbeat. Sofosbuvir is in the nucleotide analog family of medications and works by blocking the hepatitis C NS5B protein.

Sofosbuvir was discovered in 2007 and approved for medical use in the United States in 2013. It is on the World Health Organization's List of Essential Medicines.

In 2016, the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America jointly published a recommendation for the management of hepatitis C. In this recommendation, sofosbuvir used in combination with other drugs is part of all first-line treatments for HCV genotypes 1, 2, 3, 4, 5, and 6, and is also part of some second-line treatments. Sofosbuvir in combination with velpatasvir is recommended for all genotypes with a cure rate greater than 90%, and close to 100% in most cases. The duration of treatment is typically 12 weeks.

Sofosbuvir is also used with other medications and longer treatment durations, depending on specific circumstances, genotype and cost-effectiveness–based perspective. For example, for the treatment of genotypes 1, 4, 5, and 6 hepatitis C infections, sofosbuvir can be used in combination with the viral NS5A inhibitor ledipasvir. In genotype 2 and 3 HCV infections, sofosbuvir can be used in combination with daclatasvir. For the treatment of cases with cirrhosis or liver transplant patients, weight-based ribavirin is sometimes added. Peginterferon with or without sofosbuvir is not recommended in an initial HCV treatment.

Compared to previous treatments, sofosbuvir-based regimens provide a higher cure rate, fewer side effects, and a two- to four-fold reduction in therapy duration. Sofosbuvir allows most people to be treated successfully without the use of peginterferon, an injectable drug with severe side effects that is a key component of older drug combinations for the treatment of hepatitis C virus.

For people who have experienced treatment failure with some form of combination therapy for hepatitis C infection, one of the next possible steps would be retreatment with sofosbuvir and either ledipasvir or daclatasvir, with or without weight-based ribavirin. The genotype and particular combination therapy a person was on when the initial treatment failed are also taken into consideration when deciding which combination to use next. The duration of retreatment can range from 12 weeks to 24 weeks depending on several factors, including which medications are used for the retreatment, whether the person has liver cirrhosis or not, and whether the liver damage is classified as compensated cirrhosis or decompensated cirrhosis.

No adequate human data are available to establish whether or not sofosbuvir poses a risk to pregnancy outcomes. However, ribavirin, a medication that is often given together with sofosbuvir to treat hepatitis C, is assigned a Pregnancy Category X (contraindicated in pregnancy) by the FDA. Pregnant women with hepatitis C who take ribavirin have shown some cases of birth defects and death in their fetus. It is recommended that sofosbuvir/ribarivin combinations be avoided in pregnant females and their male sexual partners in order to reduce harmful fetal defects caused by ribavirin. Females who could potentially become pregnant should undergo a pregnancy test 2 months prior to starting the sofosbuvir/ribavirin/peginterferon combination treatment, monthly throughout the duration of the treatment, and six months post-treatment to reduce the risk of fetal harm in case of accidental pregnancy.