tenofovir disoproxil fumarate (TDF)
Standard DoseOne 300 mg tablet once per day (adults), with or without food. Oral powder and smaller, pediatric tablets are also available for children aged 2 and older weighing at least 22 pounds (10 kg). Take your missed dose as soon as possible unless it is less than 12 hours until your next dose. Never double your dose.
ManufacturerBrand: Gilead Sciences
AWP300 mg Tablet (brand): $1,504 / month
250 mg, 200 mg, and 150 mg
PEDIATRIC tabletS (Brand): $1,394
300 mg Tablet (Generic): $110–$1,216 / month
Powder (brand only): $3,076 / month
Potential Side Effects and Toxicity
Viread is a very well-tolerated medication with minimal side effects. The most commonly reported side effects are diarrhea, nausea, asthenia (muscle weakness), headache, depression, and abdominal pain. Other, more rarely reported side effects include rash, excessive gas, and generalized pain and achiness, including back pain. Nervous system side effects include depression, insomnia, peripheral neuropathy, and dizziness. Viread may lead to decreases in bone mineral density (BMD); patients should be monitored for osteoporosis or osteopenia. Viread is processed by the kidneys so there is risk of kidney toxicity, including acute renal failure. Before starting treatment, patients should have their creatinine clearance (CrCl) assessed. Routine monitoring of glucose and protein in the urine and of serum phosphorus should be standard of care, too. If you experience any pain in the extremities, persistent or worsening bone achiness/pain, or fractures with or without muscular pain, consult your medical provider immediately. Viread may lead to lactic acidosis, a buildup of lactic acid in the blood, which could be fatal. Signs and symptoms of lactic acidosis include feeling very weak or excessively fatigued, difficulty breathing, stomach pain with nausea and vomiting, feeling cold and chills (especially in arms and legs), dizziness and light-headedness, fast or irregular heartbeat, or unusual muscle pain. If you experience any of these symptoms contact your medical provider immediately. Two liver conditions—hepatomegaly (enlarged liver) or steatosis (fatty liver)—may occur. Signs and symptoms of these liver conditions include yellowing of the eyes and/or skin (jaundice), dark colored urine, light colored stools, nausea, loss of appetite, and pain, achiness or tenderness of the liver (lower right side of the belly, below the ribcage and next to the belly button).
Potential Drug Interactions
Be sure to tell your medical provider or pharmacist about all the medications, supplements, and herbs you take, whether they are prescribed, over-the-counter, or illicit, before starting this regimen. Report any changes to your medications as they happen. Do not take Viread with the HBV treatment Hepsera. Because Viread is related to Vemlidy (tenofovir alafenamide, TAF), the two medications cannot be taken together. Similarly, Viread cannot be taken with any of the following HIV combination medications, as they contain tenofovir (TDF or TAF): Atripla, Biktarvy, Cimduo, Complera, Delstrigo, Descovy, Genvoya, Odefsey, Stribild, Symfi, Symfi Lo, Symtuza, or Truvada. Viread reduces the level of Reyataz, meaning that Reyataz 300 mg must be boosted with Norvir 100 mg or Tybost 150 mg (taken with food) when used together. Kaletra, boosted Prezista and boosted Reyataz increase Viread levels but do not require dose adjustments. This interaction may increase Viread-related side effects; routine monitoring is recommended. Viread should be avoided with any medications that could negatively affect the kidneys, including chronic use or high doses of NSAIDS (non-steroidal anti-inflammatory drugs, such as Advil, Aleve, ibuprofen, naproxen, or Motrin).
Viread will not cure HBV—currently, no HBV medication will cure you—but it can decrease your risk of long-term complications such as cirrhosis or liver cancer.
Viread (and its related drug Vemlidy) are also HIV medications. Before starting Viread, you should be tested for HIV. If you are co-infected with HBV/HIV, you should not treat HBV without also treating your HIV to prevent resistance mutations in the HIV. In people with HBV/HIV co-infection, the combination of Emtriva and Vemlidy (or Viread) is the preferred regimen for treatment of HBV. For individuals with HBV/HCV co-infection, or who are at risk of HBV reactivation while undergoing HCV DAA treatment, Viread is one of the medications you could be prescribed to prevent this from happening. Viread is safe to take with HCV DAAs, but you should be monitored for side effects if it is used with Epclusa, Harvoni, or Vosevi and a boosted regimen for treatment of HIV.
Viread is safe to use in children aged 2 years and older, weighing at least 22 pounds (10 kg). Dosing in children is based on weight and should be done in consultation with an experienced medical provider. People with kidney disease may also need dose adjustments. See the chart below for recommendations; make sure you are routinely monitored by your medical provider while taking this treatment.