Enfuvirtide (Fuzeon)

Enfuvirtide is one of a number of medicines that you will need to take regularly.

The usual dose is two subcutaneous injections daily.

Most people experience some reaction where the injection has been given. These include pain or tenderness, swelling, redness, itchiness and skin bumps.

About enfuvirtide

Type of medicine A fusion inhibitor antiretroviral medicine
Used for Human immunodeficiency virus (HIV) infection in adults and children over 6 years of age
Also called Fuzeon®
Available as Subcutaneous injection

Enfuvirtide is an antiretroviral medicine. It is used for human immunodeficiency virus (HIV) infection. It slows the progress of HIV infection, but it is not a cure. HIV destroys cells in the body, called CD4 T cells. These cells are a type of white blood cell and are important because they are involved in protecting your body from infection. If left untreated, the HIV infection weakens your immune system so that your body cannot defend itself against bacteria, viruses and other germs. Enfuvirtide is known as a fusion inhibitor antiretroviral medicine - it works by stopping HIV from entering CD4 T cells.

Enfuvirtide is given alongside a number of other antiretroviral medicines, as part of a combination therapy. Taking three or more antiretroviral medicines at the same time is more effective than taking one alone. Taking a combination of different medicines also reduces the risk that the virus will become resistant to any individual medicine. It will be prescribed for you by a doctor who is a specialist.

Before using enfuvirtide

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking enfuvirtide it is important that your doctor or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have any problems with your liver.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.

How to use enfuvirtide

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about enfuvirtide and a full list of side-effects which you may experience from having it.
  • Use enfuvirtide exactly as your doctor has told you to. The usual dose for an adult is 90 mg twice a day. This is given as a 1 ml injection just under the skin (subcutaneous injection) on your upper arm, the outside of your thigh or your abdomen. If you are giving enfuvirtide to a child, you will be told how much of the injection to give for each dose.
  • Each injection should be given at a different site to your last few injections. You should never use an area of your skin where there is still a reaction from a previous injection.
  • Spread your injections out evenly over the day - every 12 hours if possible.
  • If you forget to have a dose at the correct time, have it when you remember, unless it is less than six hours before your next dose is due. In this case, do not have the missed dose.

How to use Fuzeon®

  1. Open the syringe pack and remove the caps on the vials.
  2. Wash your hands well and then clean the top of each vial with an alcohol wipe.
  3. Using the large (3 ml) syringe, push back the needle protection and remove the clear plastic cap. Draw 1.1 ml of air into the syringe and then insert the needle into the vial of water for injections.
  4. Press the plunger releasing the air into the vial and then turn the vial (with the syringe still attached) upside down.
  5. Slowly pull back the plunger to fill the syringe with 1.1 ml of water. Tap the syringe gently to remove any air bubbles and then check again to make sure you have 1.1 ml of water in the syringe.
  6. Remove the syringe from the vial of water. Be careful not to touch the needle with anything as you do this.
  7. Insert the needle into the vial of enfuvirtide powder, and press the syringe plunger in slowly to release the water gently into the powder. Do not shake or invert the vial.
  8. Remove the syringe from the vial, cover the needle with the needle protection and dispose of it into a safe container.
  9. Leave the vial of powder to dissolve - this may take 45 minutes. Tap the side of the vial gently to remove any bubbles and make sure the solution is particle-free.
  10. Again wipe the top of the vial with a clean alcohol swab. Remove the clear plastic cap from the small (1 ml) syringe and draw 1 ml of air into the syringe. Insert the needle into the vial, inject the air into the vial, then turn the vial upside down and gently withdraw 1 ml of solution into the syringe (or the amount your doctor has prescribed).
  11. Remove the syringe from the vial and inject the solution under your skin as you have been directed. Remember to cover the needle with the needle protection after you have finished and dispose of the syringe into a safe container.

Getting the most from your treatment

  • Keep your regular appointments with your doctor so that your progress can be monitored. You will need to have regular blood tests.
  • It is important that you have enfuvirtide and your other antiretroviral treatment regularly. This will help to prevent the HIV from becoming resistant to the medicines you are taking. Even if you miss only a small number of doses, the virus can become resistant to treatment.
  • If you develop any infection soon after you start this treatment, let your doctor know. As a result of taking antiretroviral medicines, your immune system may start fighting an infection which was present before you started the treatment, but which you may not have been aware of.
  • Follow carefully any advice your doctor gives to you about making some lifestyle changes to reduce any risk of damage to your heart and blood vessels. These may include stopping smoking, eating healthily and taking regular exercise.
  • Although treatment with antiretroviral medicines may reduce the risk of your passing HIV to others through sexual contact, it does not stop it. It is important that you use condoms.
  • It is not uncommon for people with HIV to feel low or even depressed, especially soon after the diagnosis has been made and treatment has been started. If you have any feelings of depression you should speak with your doctor straightaway.
  • Some people who have taken antiretroviral medicines (particularly over a long time) have developed a condition called osteonecrosis. This is where some bone tissue dies because there is a reduced blood supply to it. It can cause joint aches and pains, and lead to difficulties in movement. If you notice any of these symptoms, speak with your doctor.
  • If you buy any medicines, check with a pharmacist that they are suitable to take alongside your other medicines. This is because some medicines interfere with antiretrovirals and stop them from working properly.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.
  • Treatment for HIV is usually lifelong. Continue to take enfuvirtide unless you are advised otherwise, even if you feel well. This is to keep your immune system healthy.

Can enfuvirtide cause problems?

Along with their useful effects, all medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common enfuvirtide side-effects What can I do if I experience this?
Pain or tenderness, swelling, redness, itchiness and skin bumps where the injection has been given Most people experience this, particularly if injections are given in the same place. The reactions may last several days. If it becomes troublesome, discuss it with your doctor
Diarrhoea Drink plenty of water to replace lost fluids
Feeling sick, indigestion Stick to simple meals - avoid rich or spicy food. If it continues, speak with your doctor
Flu-like infections, blocked nose, conjunctivitis Ask your doctor to recommend a suitable remedy
Feeling weak or dizzy, loss of concentration Do not drive or use tools or machines until you feel better
Loss of weight, tingling or numb feelings, loss of appetite, kidney stones, muscle aches and pains, skin problems, feeling anxious, shaking, inflamed pancreas, nightmares If any of these become troublesome, let your doctor know
Changes to some blood tests Your doctor will check for this

Important: some people taking enfuvirtide have developed an allergic-type reaction. If you experience the following, stop using the injections and contact your doctor for further advice straightaway:

  • A skin rash, high temperature, sickness, sweating or chills, muscle stiffness or shaking, breathing problems, and feeling dizzy.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store enfuvirtide

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.