Alfavir 25mg Tablet

✔️ Composition of Alfavir 25mg Tablet

Tenofovir Alafenamide

✔️ Uses: Alfavir 25mg Tablet

Treatment of Chronic Hepatitis B

✔️ Side Effects of Alfavir 25mg Tablet

• Headache
• Cough
• Back pain
• Nausea and Vomiting
• Troubled breathing
• swelling of the face, finger, or lower legs
• Unusual tiredness or weakness
• Increased blood pressure
• Sleepiness
• Loss of appetite
• A general feeling of discomfort
• Diarrhea
• Dizziness

In the event of an overdose, monitor the patient for toxicity. General supportive measures should be taken, including monitoring vital signs and clinical status. Tenofovir is effectively removed by hemodialysis.

✔️ How does Alfavir 25mg Tablet work?

It prevents the multiplication of viruses in human cells. This stops the virus from producing new viruses and clears up your infection.

✔️ Quick Suggestions:

• Take it with food, as this increases the absorption of the medicine into the body.
• Tenofovir Alafenamide may cause dizziness or sleepiness. Do not drive or do anything requiring concentration until you know how it affects you.
• You may still develop infections or other illnesses associated with viral infection while taking this medication.
• You can also pass on HIV or HBV to others. Don't share needles or personal items that can have blood or body fluids on them.
• In combination with other medicines, it is used for the treatment of HIV infections.
• During treatment and for at least six months after stopping this medicine, regular blood tests are needed to monitor your liver function, level of hepatitis B virus, and blood cells in your blood.

✔️ Indications of Alfavir 25mg Tablet

Alfavir 25 mg is a nucleoside analog reverse transcriptase inhibitor indicated for the treatment of chronic hepatitis B virus (HBV) infection in adults with compensated liver disease.

✔️ Pharmacology:

Tenofovir alafenamide is a phosphonamidate prodrug of tenofovir, a 2'-deoxyadenosine monophosphate analog. It is a lipophilic compound that enters primary hepatocytes through passive diffusion and hepatic uptake transporters OATP1B1 and OATP1B3. Once inside the hepatocytes, tenofovir alafenamide is converted to tenofovir via hydrolysis, primarily by carboxylesterase 1 (CES1). The intracellular tenofovir is then phosphorylated by cellular kinases into the active metabolite tenofovir diphosphate, which inhibits HBV replication by incorporating into viral DNA through HBV reverse transcriptase, resulting in DNA chain termination. Tenofovir diphosphate is a weak inhibitor of mammalian DNA polymerases, including mitochondrial DNA polymerase γ, and shows no evidence of mitochondrial toxicity in cell cultures.

✔️ Dosage & Administration of Alfavir 25mg Tablet

Testing Before Initiation:

• Patients should be tested for HIV-1 infection before starting Alfavir 25 mg, as it should not be used alone in patients with HIV infection.
• Assess serum creatinine, serum phosphorus, estimated creatinine clearance, urine glucose, and urine protein before and during therapy as clinically appropriate.

Recommended Dosage in Adults:

• The standard dosage of Alfavir 25 mg is 25 mg (one tablet) taken orally once daily with food.
• Renal Impairment: No dosage adjustment is necessary for patients with an estimated creatinine clearance ≥ 15 mL/min or those with end-stage renal disease (ESRD) receiving chronic hemodialysis. Administer after hemodialysis on dialysis days. Alfavir 25 mg is not recommended for patients with ESRD, not on hemodialysis.
• Hepatic Impairment: No adjustment is needed for mild hepatic impairment (Child-Pugh A). It is not recommended for patients with decompensated hepatic impairment (Child-Pugh B or C).
• Pediatric Use: Safety and efficacy in patients under 18 years of age have not been established.
• Geriatric Use: No significant differences in safety or efficacy were noted in subjects aged 65 and older compared to younger subjects.
• Pediatric Use: Safety and efficacy in patients under 18 years have not been established.

✔️ Interaction

Potential Interactions:

• Tenofovir alafenamide is a substrate for P-glycoprotein (P-gp) and BCRP. Drugs affecting P-gp and BCRP activity may alter Alfavir 25 mg absorption.
• Coadministration with P-gp inducers may reduce Alfavir 25 mg absorption, decreasing therapeutic efficacy. Conversely, inhibitors may increase absorption and plasma concentration.
• Drugs affecting renal function, especially those excreted via active tubular secretion (e.g., acyclovir, cidofovir, ganciclovir), may increase tenofovir concentrations, raising the risk of adverse reactions.

✔️ Contraindications

None reported

✔️ Pregnancy & Lactation

Pregnancy

Based on data from over 660 exposures to TAF-containing regimens during pregnancy, the prevalence of birth defects was 4.2% after first-trimester exposure and 3.0% after second/third-trimester exposure. However, methodological limitations of the reporting should be considered.

Lactation

It is unclear if Tenofovir alafenamide or its metabolites are present in human breast milk or affect breastfeeding. The benefits of breastfeeding should be evaluated alongside the mother's need for the drug and any potential risks to the infant.

✔️ Precautions & Warnings

• Severe Acute Exacerbation of Hepatitis B: Discontinuing therapy may lead to severe acute exacerbations. Patients should be monitored closely after stopping treatment, and resumption of therapy may be warranted if needed.
• HIV-1 Resistance Risk: Tenofovir alafenamide should not be used alone in patients with HIV-1 due to resistance development. HIV testing is recommended before starting therapy.
• Renal Impairment: Monitor renal function closely, especially in patients with chronic kidney disease or those on nephrotoxic medications. Discontinue treatment if significant renal function declines occur.
• Lactic Acidosis/Hepatomegaly: Suspend treatment if clinical or laboratory signs of lactic acidosis or hepatotoxicity (e.g., hepatomegaly and steatosis) are observed.

✔️ Storage Conditions:

• Keep Alfavir 25 away from children
• Store at room temperature