Tenofovir Alafenamide – Antiviral Therapy

Tenofovir Alafenamide (TAF) is an innovative nucleotide reverse transcriptase inhibitor that acts as a targeted prodrug of tenofovir. The drug is indicated for the treatment of chronic hepatitis B and HIV infection. Compared to the earlier form (tenofovir disoproxil fumarate), TAF exhibits significantly higher stability in the blood plasma.

The mechanism of action of TAF involves its ability to efficiently enter infected cells (hepatocytes or lymphocytes), where it is hydrolyzed to tenofovir and then phosphorylated to active tenofovir diphosphate. The active substance is incorporated into viral DNA, causing chain termination and blocking viral replication. Because TAF delivers the active component directly into target cells, its therapeutic dose is 10 times lower than its predecessor.

The primary advantage of tenofovir alafenamide is substantially lower systemic exposure of the body to tenofovir, which significantly reduces the risk of nephrotoxicity and loss of bone mineral density, making the treatment safer for long-term use.

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Indications

Tenofovir alafenamide is used for systemic antiviral therapy:

Chronic Hepatitis B: treatment of the disease in adults and adolescents (aged 12 years and older with body weight at least 35 kg) with compensated liver disease.
HIV-1 Infection: as part of combination antiretroviral therapy in adults and children to suppress viral load.
Patients with Renal Impairment: therapy for individuals with creatinine clearance ≥15 mL/min who are not candidates for other forms of tenofovir.
Prophylaxis: use in pre-exposure and post-exposure HIV prophylaxis regimens as part of combination products.

Dosage and administration

The dosage of tenofovir alafenamide depends on the disease and the composition of the medication used.

For Hepatitis B: the standard dose is 25 mg once daily (as a single-agent product).
For HIV Infection: the dosage is typically 10 mg or 25 mg as part of fixed-dose combinations with other antiretroviral agents.
Administration Rules: the tablet should be taken orally with food to ensure optimal absorption. The medication should be taken at the same time every day.
Missed Dose: if less than 18 hours have passed since the missed dose, take it immediately. If more than 18 hours, skip the dose and return to the regular schedule.
Duration of Therapy: treatment for chronic infections is usually long-term and must not be interrupted without medical consultation.

The use of tenofovir alafenamide is restricted in the following conditions:

Hypersensitivity: known allergy to tenofovir alafenamide or any excipients in the tablet.
Severe Renal Impairment: not recommended for patients with creatinine clearance < 15 mL/min who are not receiving hemodialysis.
Decompensated Hepatic Impairment: safety in this patient group has not been fully established.
Pediatric Use: not used in children under 12 years of age or with body weight less than 35 kg (for the 25 mg dose).
Co-administration with Rifampin: use with strong P-glycoprotein inducers is not recommended, as it drastically reduces TAF efficacy.

Tenofovir alafenamide is generally well-tolerated, though the following adverse reactions may occur:

General Symptoms: headache (most common), fatigue, and dizziness.
Digestive System: nausea, diarrhea, abdominal pain, and flatulence.
Skin Reactions: rash and pruritus.
Laboratory Parameters: elevated alanine aminotransferase (ALT) levels after starting or stopping therapy, and increased blood lipid levels.
Musculoskeletal System: joint pain (rare, significantly less frequent than with tenofovir disoproxil).

Frequently Asked Questions

Tenofovir alafenamide (TAF) is a next-generation antiviral medication. It is used to treat chronic hepatitis B in adults and adolescents, as well as part of combination therapy for HIV. The drug works by blocking the virus's ability to replicate, thereby reducing the viral load in the body.

The primary advantage of Tenofovir Alafenamide (TAF) is its improved safety profile for kidneys and bones. TAF delivers the active ingredient more efficiently directly to liver cells, allowing for a much lower dose (25 mg instead of 300 mg) and significantly reducing the risk of systemic side effects.

Vemlidy is the original drug developed by Gilead. Indian generics (such as HepBest or Tafero) available on Unifarm contain the same active ingredient in a 25 mg dosage. They are manufactured under license or in strict accordance with international GMP standards and are several times more affordable than the original.

The standard dosage is one tablet (25 mg) once daily. It is recommended to take the medication with food, swallowing the tablet whole with water. It is important to stay consistent and take the medicine at the same time every day to maintain stable protection levels.

The most common side effect is a headache. Nausea, abdominal pain, fatigue, or a rash may also occur. Unlike previous generations of tenofovir, TAF's impact on bone mineral density and kidney function is minimal.

The Unifarm website offers TAF generics at prices that make long-term chronic hepatitis B treatment affordable. The cost depends on the manufacturer and the number of packs ordered. Current prices are listed on the product page in the catalog.

You can order the medication online via the Unifarm website or by phone. We deliver orders throughout Ukraine via Nova Poshta. If you need advice on choosing a manufacturer (Mylan, Natco, Hetero), our managers will provide all the necessary information.