Medication Information Leaflet

What are these medications for?

Tenofovir Alafenamide (TAF) and Tenofovir Disoproxil Fumarate (TDF) are medications used to treat infections caused by viruses such as Hepatitis B and human immunodeficiency virus (HIV). They work by preventing such viruses from reproducing and hence reducing the amount of the virus in the body.

TAF and TDF are not cures for hepatitis and HIV. They must be taken consistently every day to slow the progression of the disease.

How should I take/use this medication?

• TAF should be taken with or after food for better absorption, while TDF may be taken without regards to meals.
• It is important that you take these medications daily at a regular time.
• Do not miss any doses as this may make the medication less effective.
• Do not stop taking your medication without consulting your healthcare professional. Stopping medication may result in worsening of the infection.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

• You are allergic to this medication or any of the other ingredients of this medication.
• You are pregnant, planning to become pregnant, or breastfeeding.
• You are taking any other medications, including supplements, traditional medications and herbal remedies.

What are some possible side-effects of this medication?

• Minor side effects include stomach pain, diarrhoea, nausea, vomiting, headache.
  • These usually resolve on their own after a while. Consult your doctor if these side effects persist and/or bother you.
• These medications may lower your bone mineral density (bone quality).
  • Your doctor may ask you to go for scheduled bone scans where required.
  • You may consider having more calcium-rich foods in your diet or consult your doctor for a calcium/vitamin D supplement to help maintain healthy bones.
• These medications may affect your kidney function.
  • Your doctor will monitor this through blood and urine tests.
  • See your doctor immediately if you develop any signs of kidney problems such as being unable to pass urine, change in your daily volume of urine, blood in urine, or a big weight gain.

What are some rare but serious side-effects that I need to seek medical advice immediately?

Stop your medication and see your healthcare professional immediately if you experience any symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

Rarely, TAF and TDF can cause a build-up of acid in your blood (lactic acidosis). Consult your doctor if you experience signs of lactic acidosis such as:

• Fast breathing or shortness of breath
• Fast or irregular heartbeat
• Dizziness or light-headedness
• Stomach discomfort, nausea or vomiting
• Extreme tiredness or weakness
• Muscle pain or cramps

TAF and TDF can also rarely cause liver problems. Consult your doctor if you experience signs of liver problems such as:

• Yellowing of the skin and eye white
• Dark-coloured urine
• Light-coloured stools
• Lower abdominal pain
• Nausea
• Loss of appetite

What food or medication should I avoid when I take this medication?

Inform your healthcare professional if you are currently taking any one of the following medications:

• Adefovir for Hepatitis B treatment
• Epclusa, Harvoni, Vosevi for Hepatitis C treatment
• Non-steroidal anti-inflammatory agents (NSAIDs) for pain or fever

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Pack the medication into a bag and bring it back to the pharmacy where you received the medication from.

Disclaimers

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on August 2023