tenofovir alafenamide, or TAF (25 mg)
Standard DoseOne 25 mg tablet once per day, with food. There is no dose adjustment for people with creatinine clearance (CrCl) greater than 15 mL/min or for people with end stage kidney disease who are on hemodialysis. On days of dialysis, Vemlidy should be taken upon completion of dialysis. Vemlidy is safe for people with mild liver damage (Child-Pugh A), but it should not be used in patients with decompensated cirrhosis (Child-Pugh B or C). Take missed dose as soon as possible, unless it is closer to the time of your next dose. Do not double up on your next dose.
AWP$1,343 / month
Potential Side Effects and Toxicity
Vemlidy is a very well-tolerated medication with minimal side effects. The most commonly reported side effects were headache, abdominal pain, fatigue, cough, nausea, and back pain. Not everyone experiences side effects, and among those who did, approximately 1% had to stop taking Vemlidy. As Vemlidy is processed by the kidneys, there is some risk of kidney toxicity, although the risk is significantly lower compared to a similar medication, Viread. Before starting it, patients should have their 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.
There are two potential serious side effects when taking Vemlidy: lactic acidosis and two serious liver conditions. These are, however, more common with older medications in the same class as Viread (NRTI) and are unlikely to occur. (1) Lactic acidosis: The buildup of lactic acid in the blood that 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. (2) 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 herbal products you take, whether they are prescribed, over-the-counter, or illicit, before starting this regimen, and inform them of any changes as they happen. As Vemlidy is related to Viread (tenofovir disoproxil fumarate, TDF), the two medications cannot be taken together. Vemlidy cannot be taken with any of the following HIV combination medications, as they also contain tenofovir (duplicate therapy): Atripla, Symfi, Symfi Lo, Complera, Odefsey, Descovy, Truvada, Biktarvy, Stribild, Genvoya, Cimduo, or Delstrigo. If taken with the anticonvulsant carbamazepine, Vemlidy dosage should be increased to two tablets (50 mg) once per day. Vemlidy should not be taken with oxcarbazepine, phenobarbital, or phenytoin as they reduce the concentrations of tenofovir and may reduce its effectiveness. Vemlidy should not be taken with the rifamycin antimicrobials, such as rifabutin, rifampin, and rifapentine. Vemlidy should not be taken with St. John’s wort, and in general, herbal products should be avoided due to lack of information regarding potential for interaction.
Vemlidy was approved for treatment of HBV in 2016. It’s related to Viread, but is given as a smaller dose that is more efficiently delivered so the risks of kidney disease and loss of bone density appear to be less. Before starting Vemlidy, you should be tested for HIV. If you are co-infected with HBV/HIV, you should not treat HBV without also treating HIV to prevent resistance mutations in the HIV. Two other HIV medications —Epivir and Emtriva —also work against HBV, although Epivir is no longer preferred for the treatment of HBV. In people with HBV/HIV co-infection, the combination of Emtriva and Vemlidy (or Viread) is the preferred regimen for treatment of HBV.
Abrupt discontinuation of Vemlidy may cause a severe, acute exacerbation of hepatitis B, which can result in hepatic decompensation and liver failure. If Vemlidy is discontinued, your doctor should closely monitor you for symptoms of exacerbation. Do not stop this medication without talking to your doctor first.
For individuals with HBV/HCV co-infection, or those at risk of HBV reactivation while undergoing HCV DAA treatment, Vemlidy is one of the medications you could be prescribed to prevent this from happening. See HBV Reactivation for more information and consult your medical provider.
Vemlidy is not currently approved for use in children for treatment of HBV.