Tenofovir Alafenamide (Oral)

Tenofovir alafenamide is a drug that is used to treat adults with chronic hepatitis B virus infection (HBV) who also have compensated liver disease.

Overview

Tenofovir alafenamide is a drug that is used to treat adults with chronic (long-term) hepatitis B virus infection (HBV) who also have compensated liver disease.

The medication works by slowing the growth of the virus or stopping it altogether. People suffering from chronic hepatitis B virus infection can develop serious liver disease, including cirrhosis and cancer.

The drug comes in tablet form and is only available on prescription from your doctor or treating physician. Tenofovir alafenamide is sold in the US under the brand name Vemlidy.

Conditions treated

  • Hepatitis B virus infection plus compensated liver disease

Type of medicine

  • anti-viral
  • tablet

Side effects

Despite the many benefits that tenofovir alafenamide can bring, some patients may suffer a few side effects. Most of these side effects will not affect you, but if you do notice any unusual or unpleasant reactions, you should talk to your doctor in case the effects require further medical attention.

There are some side effects that are often experienced by patients who are taking tenofovir alafenamide, including headaches and a cough. These effects often resolve themselves within a week or two, when your body gets used to the new medication. If the effects persist or become a particular nuisance, ask your doctor for advice on how to prevent and manage them.

There are some more serious side effects that can affect a small percentage of users of tenofovir alafenamide. If you begin to notice any of the following, you should contact your doctor for advice immediately.

  • stomach pains or discomfort in the abdomen
  • a general feeling of discomfort
  • dark or bloody urine, decreased amount or frequency of urine
  • diarrhea, light-colored stools
  • poor appetite
  • rapid, shallow breathing, or breathing problems
  • hypertension
  • feeling very thirsty
  • pain in the side or lower back
  • cramps or muscle pains
  • nausea and vomiting
  • excessive tiredness
  • swellings of the lower legs, face, or fingers
  • jaundice
  • weight gain

This list of side effects is not exhaustive. If you notice any other unusual effects or if you begin to feel generally unwell after you begin taking tenofovir alafenamide, you should report them to your doctor or specialist immediately.

Dosage

You must take tenofovir alafenamide as prescribed to you by your doctor. You should take this medication with food. Swallow the tablets whole. Do not crush, chew, or split the tablets.

When you receive your prescription, you will be given a Medication Guide. Read the Guide thoroughly so that you understand how to take the tablets. If you have any questions, ask your doctor or pharmacist.

You should only take this medicine as directed by your doctor. Do not take more than the prescribed dose. Do not increase the frequency of the dose you have been prescribed, and do not continue taking the drug for longer than instructed by your treating physician. Do not miss out any doses.

For chronic hepatitis B infection

  • adults: 25 mg, once daily with food
  • children: use and dosage as instructed by your doctor

In order for tenofovir alafenamide to work properly, it is important that you continue taking it for the whole course prescribed to you by your doctor. If your supply of medication is getting low, contact your doctor for a repeat prescription so that you don't run out.

If you forget to take your tablet, you should try to take it as soon as possible. If it is close to the time for your next dose, miss one dose and revert to your usual schedule. Do not double-dose.

The dose of this medication may be different for other patients. Follow your doctor's instructions or the directions given on the drug package label. Do not adjust your dose, unless instructed to by your specialist.

Do not share your prescription medication with anyone else.

If you find that you suddenly feel worse or you think that your condition has not improved after you begin taking this medication, you should consult your doctor straight away.

In the event that you accidentally take an overdose of the drug, you may experience breathing problems or have fainting episodes. If you think you may have overdosed, seek your doctor's advice immediately or call 911.

Major drug interactions

Some types of medication should not be used together, as this can adversely affect how your medicines work. Interactions between different drugs can also increase the risk of serious side effects. However, sometimes two or more different drugs may be used together, even though an interaction may occur. In this case, your doctor may need to change the dose of one of your prescription drugs. Your doctor or pharmacist might also be able to suggest some ways in which you can manage or prevent the side effects of the interactions.

It is helpful for your doctor if you compile a list of all the medicines that you take. This list should include prescription and non-prescription drugs, herbal remedies, and vitamin supplements. Give this list to your doctor before you start taking tenofovir alafenamide. Do not alter the dose or frequency of any of your medications without first checking with your doctor.

There are a number of medicines that may interact with tenofovir alafenamide including:

  • Tipranavir
  • St John's Wort
  • Rifapentine
  • Rifampin
  • Rifabutin
  • Phenytoin
  • Phenobarbital
  • Oxcarbazepine
  • Carbamazepine

Tell your doctor if you are already taking any of these drugs.

Warnings

While you are taking tenofovir alafenamide, you must attend meetings with your doctor for regular check-ups. These appointments are very important, as they give your doctor the opportunity to check that the medication is working correctly. You will also be able to discuss any side effects that you may be suffering and voice any concerns that you may have about your new drug regimen. You may also have routine blood tests done to make sure that there are no unwanted effects that the new medication is causing.

You must tell your treating physician if you are already taking any other form of medication. This includes over-the-counter products, herbal remedies, and vitamin supplements. It is also imperative that you tell your doctor if you have any known allergies to food colourings, particular foodstuffs, preservatives, or animal derivatives.

There are some other medical problems that may affect how this medicine works. You must tell your doctor if you suffer from any other medical conditions, especially:

  • Fanconi syndrome
  • kidney failure

This medication can make these conditions worse.

  • end-stage kidney disease requiring dialysis
  • liver disease, decompensated

The effects of tenofovir alafenamide can be increased with these conditions, due to the slower removal of the drug from the body.

If you think you could be pregnant, tell your doctor. Although there are no studies to show that this drug can harm an unborn baby, you should discuss the pros and cons of using the medication with your doctor. It is not known if this drug passes into breast milk.

If you have HIV, you must be taking a combination antiretroviral drug regimen as prescribed to you by your doctor before you begin your course of tenofovir alafenamide.

There are two rare but very serious reactions that can occur in patients who are taking this medication: lactic acidosis and liver toxicity. These conditions occur more commonly in females, people who are very overweight, and in those who have been taking anti-HIV medication for a long period of time. If you experience any of the following symptoms, you should contact your doctor immediately.

  • severe stomach cramps or discomfort
  • nausea
  • vomiting
  • diarrhea
  • decreased appetite
  • general feeling of discomfort
  • muscle cramps or pain
  • feeling unusually weak or tired
  • breathing problems
  • jaundice

Long-term use of this medication can cause injury to the kidneys. Your doctor will require blood tests in order to monitor this throughout the course of your treatment. Avoid all other medication that may cause injury to the kidneys, such as some other antiviral medications and NSAID drugs.

Storage

You should keep your supply of tenofovir alafenamide in the sealed, airtight container it was supplied in. Use only medication that is dispensed in its original container.

Store your medication at room temperature. Do not freeze the drug, expose it to direct sunlight or to sources of heat. Keep the tablets dry.

Always keep your medicine where it cannot be accessed by children or pets. If a pet does consume tenofovir alafenamide, you should seek immediate veterinary advice.

Do not keep any unwanted medication. You should not use any medication that has exceeded its expiry date. Do not flush unwanted medication down the toilet or drain. Do not discard tablets with your trash. Tenofovir alafenamide tablets could easily be mistaken for candy and consumed by a child.

If you are not sure of how to dispose of unwanted medication, ask your pharmacist or doctor for advice.

Summary

Tenofovir alafenamide is a prescription-only drug that is used to treat adults with chronic (long-term) hepatitis B virus infection (HBV) that is exacerbated by compensated liver disease. The drug acts by slowing the growth of the virus or arresting it completely. Tenofovir alafenamide is sold in the US under the brand name Vemlidy and comes in tablet form.

There are some side effects that patients taking tenofovir alafenamide do experience fairly frequently, including headaches and a cough. In addition, patients who have a history of kidney failure, Fanconi syndrome, end-stage kidney disease requiring dialysis, and decompensated liver disease should be aware that this medication may make these conditions worse.

Tenofovir alafenamide is very effective in managing and controlling hepatitis B virus infection with compensated liver disease. In order to get the best results from following a course of treatment with this drug, you must work closely with your treating physician to work out the right dose and dosage schedule for you. This process will mean that you must attend for regular assessments with your doctor or specialist where you will have blood and urine tests. It is essential that you attend all your scheduled appointments, as they are necessary to be sure that your course of treatment is fully effective and that you are not suffering any unwanted side effects.

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Last Reviewed:
December 25, 2017
Last Updated:
April 23, 2018
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