Tenofovir AF

Tenofovir AF is used for the treatment of chronic hepatitis B virus (HBV) infection in adults with compensated liver disease.

Tenofovir AF is available under the following different brand names: Vemlidy.

Dosages of Tenofovir AF:

Dosage Forms and Strengths

Tablet

• 25mg

Dosage Considerations – Should be Given as Follows:

Chronic Hepatitis B Infection

• Indicated for treatment of chronic hepatitis B virus (HBV) infection in adults with compensated liver disease
• 25 mg orally once daily with food

Dosage Modifications

Renal impairment

• Mild, moderate, or severe: No dosage adjustment required
• ESRD (CrCl less than 15 mL/minute): Use not recommended in patients who are not receiving hemodialysis; in patients receiving chronic hemodialysis, administer drug after completion of hemodialysis

Hepatic impairment

• Mild (Child-Pugh A): No dosage adjustment required
• Decompensated (Child-Pugh B or C) hepatic impairment: Use not recommended

Dosing Considerations

• Test for HIV-1 infection before initiating; tenofovir alone should not be used in patients with HIV infection
• Assess serum creatinine, phosphorous, estimated CrCl, urine glucose, and urine protein before initiating and periodically throughout treatment
• Children under 18 years: Safety and efficacy not established

Common side effects of tenofovir AF include:

• Headache
• Bone mineral density decline
• Abdominal pain
• ALT greater than 5 times ULN
• Cough
• Fatigue
• Nausea
• LDL-cholesterol fasted greater than 190 mg/dL
• Back pain
• Glycosuria 3+ and greater
• Nausea
• Joint pain
• Diarrhea
• Indigestion/heartburn
• AST greater than 5 times ULN
• Creatine kinase 10 times ULN or greater
• Serum amylase greater than 2 times ULN

Other side effects of tenofovir AF include:

• Severe acute exacerbation of hepatitis B in patients with HBV infection

Postmarketing side effects of tenofovir AF reported include:

• Skin and subcutaneous tissue disorders: Angioedema, urticaria

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

• Tenofovir AF has no listed severe interactions with other drugs.
• Serious interactions of tenofovir AF include:
  • letermovir
• Moderate interactions of tenofovir AF include:
  • acalabrutinib
  • apalutamide
  • cabozantinib
  • darolutamide
  • duvelisib
  • elagolix
  • fostamatinib
  • glecaprevir/pibrentasvir
  • ifosfamide
  • istradefylline
  • orlistat
  • regorafenib
  • safinamide
  • sarecycline
  • sofosbuvir/velpatasvir
  • stiripentol
  • tafamidis
  • tafamidis meglumine
• Tenofovir AF has no listed mild interactions with other drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

• This medication contains tenofovir AF. Do not take Vemlidy if you are allergic to tenofovir AF or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Black Box Warnings

Hepatitis B exacerbation

• Severe acute exacerbations of hepatitis B were reported in patients who have discontinued therapy for hepatitis B
• Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue therapy
• Resumption of therapy for hepatitis B may be warranted

Lactic acidosis

• Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) were reported with the use of nucleoside analogues alone or in combination

Contraindications

• None

Effects of Drug Abuse

• No information is available

Short-Term Effects

• See "What Are Side Effects Associated with Using Tenofovir AF?”

Long-Term Effects

• See "What Are Side Effects Associated with Using Tenofovir AF?”

Cautions

• Lactic acidosis and severe hepatomegaly with steatosis, including fatalities, reported with nucleoside analogs, including tenofovir disoproxil fumarate in combination with other antiretrovirals; most were reported in women; obesity and prolonged nucleoside exposure may be risks factors
• Discontinuation of anti-hepatitis B drugs may result in severe acute exacerbations of hepatitis B; all patients should be tested for the presence of chronic hepatitis B virus (HBV) before or when initiating therapy
• Resumption of anti-hepatitis B therapy may be warranted, in patients with advanced liver disease or cirrhosis, since posttreatment exacerbation of hepatitis may lead to hepatic decompensation and liver failure
• Owing to the risk of development of HIV-1 resistance, tenofovir AF alone is not recommended for the treatment of HIV-1 infection; test for HIV-1 before initiating treatment
• Persistent or worsening bone pain, pain in extremities, fractures and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function in patients at risk of renal dysfunction
• Renal impairment, including cases of acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with the use of tenofovir prodrugs; this has not been observed with tenofovir AF in clinical trials; before or when initiating therapy, and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients; in patients with chronic kidney disease, also assess serum phosphorus; discontinue therapy in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome

Drug interaction overview

P-gp and BCRP

• P-gp and BCRP substrate; drugs that strongly affect these transporters may lead to changes in tenofovir AF absorption
• Drugs that induce P-gp result in decreased tenofovir AF absorption and plasma concentrations, which may lead to loss of therapeutic effect (e.g., carbamazepine, oxcarbazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, St John’s wort)
• Drugs that inhibit P-gp and BCRP may increase tenofovir AF absorption and plasma concentration

Drugs affecting renal function

• Tenofovir is primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion
• Coadministration of tenofovir AF with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, and this may increase the risk of adverse reactions
• Some examples include acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides, high-dose or long-term NSAD use

Pregnancy and Lactation

• There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to tenofovir AF during pregnancy; healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258- 4263.
• It is unknown if tenofovir AF is distributed in human breast milk. Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for tenofovir AF, and any potential adverse effects on the breastfed infant from the drug or the underlying maternal condition.