Tenofovir disoproxil fumarate (TDF), commonly sold under the brand name Viread and as a generic, is an antiviral medication used to treat chronic hepatitis B and manage HIV/AIDS infection. It works by preventing the viruses from making copies of themselves in the body. 

Key Information

• Uses: TDF is used to treat HIV-1 infection (always in combination with other antiretrovirals) and chronic hepatitis B infection in adults and some children. It can also be part of pre-exposure prophylaxis (PrEP) to prevent HIV infection in high-risk individuals.

• Dosage: The typical adult dose is one 300-mg tablet taken orally once daily, with or without food. It's crucial to take the medication exactly as prescribed and not skip doses, as this can lead to drug resistance.