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Tenofovir alafenamide is an antiviral for chronic hepatitis B and an ingredient in several HIV treatment and prevention combinations. Its use depends on the complete product. Browse available tenofovir alafenamide products at KwickPharmacy. Compare every active ingredient, strength, manufacturer, pack size and prescription status before ordering.
Tenofovir alafenamide (TAF) is an antiretroviral medicine that belongs to the nucleotide reverse transcriptase inhibitor (NRTI) class. It is a prodrug that is converted inside cells into the active form, tenofovir diphosphate. The active drug inhibits HIV reverse transcriptase and interferes with viral DNA synthesis, helping reduce HIV replication.
Vemlidy is the established single-ingredient brand of tenofovir alafenamide and is used for the treatment of chronic hepatitis B. TAF is also included in several combination medicines, including Descovy, Biktarvy, Genvoya, Odefsey, and Symtuza. These products contain different combinations of active ingredients and have different approved uses, so they should not be considered interchangeable.
The appropriate TAF-containing medicine depends on the condition being treated, other medicines in the regimen, kidney and liver function, and the individual's clinical circumstances.
Vemlidy is approved for eligible adults and children with chronic hepatitis B. It suppresses the virus and helps protect the liver but does not remove HBV from the body.
For HIV-1, TAF forms part of a complete combination regimen. Descovy, containing emtricitabine and TAF, is also authorised as PrEP for certain HIV-negative people. TAF alone is not complete HIV treatment or PrEP.
Tenofovir alafenamide (TAF) is a prodrug that enters cells and is converted into the active metabolite tenofovir diphosphate. Tenofovir diphosphate inhibits viral reverse transcriptase, an enzyme needed for viral DNA synthesis and replication.
By interfering with this process, TAF helps suppress the replication of HIV and, in appropriate treatment regimens, hepatitis B virus (HBV). Its antiviral effect helps control these infections while treatment is continued, but TAF does not eliminate HIV from the body or provide a cure for HIV infection. It is also not considered a cure for chronic hepatitis B.
Tenofovir alafenamide (TAF) delivers the active tenofovir metabolite efficiently into cells while generally producing lower circulating plasma tenofovir concentrations than tenofovir disoproxil fumarate (TDF). Because of its greater intracellular delivery, TAF can be used at a lower dose than TDF in many approved formulations.
Compared with TDF-containing regimens, TAF-containing regimens are generally associated with less impact on kidney function and bone mineral density in appropriate patients. However, TAF can still affect the kidneys and is not suitable for everyone.
The choice between TAF, TDF, or another antiviral depends on whether HIV or chronic hepatitis B is being treated, kidney and liver function, other medicines being taken, potential drug interactions, and the specific treatment regimen. TAF should be used only as prescribed and should not be switched with another tenofovir formulation without medical guidance.
The labelled Vemlidy dosage for chronic hepatitis B is 25 mg once daily with food. HIV combinations may contain TAF 10 mg or 25 mg because other ingredients can change how much medicine reaches the body. The strength of one product must never be used as dosing instructions for another.
Follow the complete prescription. Kidney impairment, dialysis, age, weight and interactions may affect selection or timing. Do not stop or switch without medical advice.
Tenofovir alafenamide (TAF) is an established treatment for chronic hepatitis B, but liver function and treatment response should be monitored as recommended by a healthcare professional. Vemlidy (TAF) is not recommended for patients with decompensated liver disease.
Stopping TAF in people being treated for chronic hepatitis B can cause a serious acute exacerbation of hepatitis B. This warning also applies when an HBV-active medicine in an HIV treatment regimen is discontinued. Patients who stop treatment should be monitored closely for several months for signs of worsening hepatitis B.
Rare but serious warnings associated with tenofovir-containing medicines include lactic acidosis and severe hepatomegaly with steatosis (fatty enlargement of the liver). Seek medical attention if symptoms suggest a serious liver or metabolic problem.
Tenofovir alafenamide generally has a more favourable renal safety profile than tenofovir disoproxil fumarate (TDF) because it results in lower circulating tenofovir concentrations. However, TAF is not completely free of kidney-related risks.
Kidney problems, including acute kidney injury, proximal renal tubulopathy, and Fanconi syndrome, have been reported with TAF-containing medicines. Healthcare professionals may assess kidney function before and during treatment using tests such as serum creatinine and estimated creatinine clearance. Additional urine or blood tests may be appropriate depending on the medicine, existing kidney disease, and individual risk factors.
Renal dosing recommendations and eligibility requirements vary between TAF-containing products, so patients should follow the specific instructions for their prescribed medicine.
TAF and TDF are different prodrugs that deliver the active antiviral tenofovir. TAF is used at a lower dose in many formulations and generally produces less systemic exposure to tenofovir, which is associated with more favourable effects on kidney function and bone mineral density than TDF in many treatment settings.
However, TDF may remain preferable in certain situations because the two medicines have different approved uses, formulations, PrEP indications, clinical evidence, effects on lipid levels, and costs. TAF and TDF are not dose-equivalent and should not be taken together unless specifically directed by a healthcare professional.
The choice between TAF vs TDF should be based on the condition being treated, kidney and bone health, other medicines, potential interactions, and the individual's overall treatment needs.
Headache is a commonly reported adverse reaction with single-ingredient Vemlidy. Side effects can vary depending on the specific TAF-containing medicine. Some combination products may be associated with nausea, diarrhoea, tiredness, abdominal discomfort, dizziness, sleep disturbances, or changes in body weight and lipid levels.
Contact a healthcare professional if side effects are persistent or concerning. Seek urgent medical attention for severe weakness, unusual muscle pain, rapid or difficult breathing, persistent vomiting, severe abdominal pain, substantially reduced urination, swelling, yellowing of the skin or eyes, or symptoms of a severe allergic reaction. These may indicate a serious metabolic, kidney, liver, or allergic reaction.
Before starting, disclose kidney or liver disease, HIV or HBV status, pregnancy, breastfeeding and all medicines or supplements. Some seizure medicines, rifamycin antibiotics and St John’s wort can lower TAF levels and reduce effectiveness. Medicines that affect kidney function, including high-dose or repeated anti-inflammatory painkillers, may increase renal risk.
HIV testing is required before Vemlidy is used for hepatitis B because TAF alone can encourage HIV resistance. PrEP also requires a confirmed negative HIV test before starting and regular testing during use.
Store tenofovir alafenamide tablets at temperatures below 30°C (86°F) in the original, tightly closed container. Protect the tablets from excess moisture and keep any moisture-absorbing packet supplied with the medicine inside the container.
Keep tenofovir alafenamide and all medicines out of the reach of children. Do not use tablets that are expired, damaged, or have been stored outside the recommended conditions without checking with a pharmacist.
TAF is a prodrug that becomes active tenofovir inside cells. It is different from TDF and cannot be substituted milligram for milligram.