About 2.5 million persons in the US had hepatitis C between 2017 and 2020. Guidelines from the American Association for the Study of Liver Diseases (AASLD) and the Infectious Diseases Society of America (IDSA) on management of hepatitis C virus (HCV) infection were updated in 2023.

Harvoni, a once-daily fixed-dose combination of the direct-acting antiviral agents ledipasvir and sofosbuvir approved by the FDA in 2014 for treatment of hepatitis C virus (HCV) genotype 1 infection,1 has now been approved for use in patients infected with HCV genotype 4, 5, or 6, and in patients co-infected with HCV and HIV-1. A 12-week course of treatment with Harvoni plus ribavirin has also been approved as an alternative to 24 weeks of Harvoni alone for treatment-experienced, cirrhotic patients with HCV genotype 1 infection.HCV genotypes 4, 5, and 6 are responsible for <2% of HCV cases...

The FDA has approved Mavyret (Abbvie) and Vosevi (Gilead), two new fixed-dose combinations of direct-acting antiviral (DAA) drugs, for treatment of chronic hepatitis C virus (HCV) infection caused by any of the six major HCV genotypes in patients without cirrhosis or with compensated cirrhosis. Both are approved for use in treatment-experienced patients. Mavyret is also approved for treatment-naive patients.

The FDA has approved a fixed-dose combination (Harvoni [har voe' nee] – Gilead) of sofosbuvir and ledipasvir (led' i pas' vir), two oral direct-acting antiviral agents, for treatment of chronic hepatitis C virus (HCV) genotype 1 infection. Genotype 1 is responsible for 70-80% of HCV infections in the US. Sofosbuvir (Sovaldi) was approved earlier for use in combination with other antiviral drugs for treatment of HCV infection. Ledipasvir is a new drug.

The FDA has approved daclatasvir (Daklinza – BMS), an oral direct-acting antiviral drug, for use with sofosbuvir (Sovaldi) for treatment of chronic hepatitis C virus (HCV) genotype 3 infection. Daclatasvir is the first drug approved for this indication that does not require the addition of interferon or ribavirin. It is approved in Japan and Europe in combination with other drugs for treatment of HCV genotypes 1-4.

The drugs of choice for treatment of viral infections (other than HIV) and their dosages are listed in Tables 1-6 on the pages that follow. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used for the prevention of viral infections are discussed elsewhere.

View Figure 1: Treatment of Hepatitis C Virus Infection in Treatment-Naive Adults

The single sentence on vaccination site care in our recent article on Smallpox Vaccination (Vol. 45, page 2) needs clarification. In the past, the vaccination site was generally left uncovered, but current plans for Phase I call for it to be covered with both gauze to absorb liquid and a semipermeable membrane such as an Opsite dressing to prevent spread of the virus. This correction has been made in the web version of the issue.

The severity and rapid spread of COVID-19 (caused by SARS-CoV-2) have raised questions about the use of some drugs in patients with the disease and whether currently available drugs could be effective in treating it. Definitive answers are lacking, but some recommendations can be made. For additional information on specific drugs, see our table Some Drugs Being Considered for Treatment of COVID-19.

Concerns have arisen anew about possible use of biological weapons. The pathogens considered most likely to be used for this purpose are discussed in this article. A good source for additional information is www.usamriid.army.mil/education/bluebook.html.