An Overview of Fuzeon (Enfuvirtide, T-20)

Brand Name: Fuzeon
Other Name(s): T-20
Drug Class: Fusion inhibitor

Fuzeon vial


Enfuvirtide must be given as an injection (a shot). Almost all people taking the medicine have a reaction at the location where the shot is given (called an injection site reaction). Injection site reactions with enfuvirtide are usually mild to moderate but occasionally can be severe. Reactions on the skin where enfuvirtide is injected include:

  • Itching
  • Swelling
  • Redness
  • Pain or tenderness
  • Hardened skin
  • Bumps

Contact your health care provider right away if you have signs of infection at an injection site (oozing, increasing heat, swelling, redness, or pain).

Enfuvirtide can cause serious side effects. These include severe allergic reaction and possibly pneumonia.

Contact your health care provider right away if you have any of the following symptoms, alone or in combination, that could be signs of a severe allergic reaction:

  • Trouble breathing
  • Fever with vomiting and a skin rash
  • Blood in your urine
  • Swelling of your feet
  • Chills
  • Shivering
  • Low blood pressure

Contact your health care provider right away if you have any of the following symptoms that could be signs of pneumonia:

  • Cough
  • Fever
  • Trouble breathing, including rapid breathing or shortness of breath

While taking enfuvirtide, it is important to keep all of your appointments with your health care provider.

What Is Enfuvirtide?

Enfuvirtide is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children 6 years of age and older. Enfuvirtide is for people whose HIV infection is not well controlled by ongoing treatment with other HIV medicines. Enfuvirtide is always used in combination with other HIV medicines.

Enfuvirtide belongs to a class (group) of HIV drugs called fusion inhibitors. Fusion inhibitors block HIV from getting into and infecting certain cells of the immune system. This prevents HIV from multiplying and can reduce the amount of HIV in the body.

HIV medicines can't cure HIV/AIDS, but taking a combination of HIV medicines (called an HIV regimen) every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission.

What Should I Tell My Health Care Provider Before Taking Enfuvirtide?

Before taking enfuvirtide, tell your health care provider:

  • If you are allergic to enfuvirtide or any other medicines.
  • If you have any other medical conditions in addition to HIV.
  • If you are pregnant or plan to become pregnant. Whether enfuvirtide can harm an unborn baby is unknown. Enfuvirtide should be used during pregnancy only if clearly needed. Talk to your health care provider about possible risks with taking enfuvirtide when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you have HIV or are taking enfuvirtide.
  • If you are using hormone-based birth control (such as pills, implants, or vaginal rings). For more information about using birth control and HIV medicines at the same time, view the AIDSinfo HIV and Birth Control infographic.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Enfuvirtide may affect the way other medicines or products work, and other medicines or products may affect how enfuvirtide works.

How Should I Take Enfuvirtide?

Enfuvirtide comes as a powder that is mixed with sterile water to give as an injection (a shot). The enfuvirtide powder, sterile water, and everything else needed to give the injection come in a convenience kit. The kit includes:

  • 60 vials of enfuvirtide powder. Each vial contains 108 mg of enfuvirtide powder.
  • 60 vials of sterile water for injection.
  • 60 syringes for mixing.
  • 60 syringes for injecting.
  • Instructions for mixing and injecting enfuvirtide.
  • Patient information about enfuvirtide.

Take enfuvirtide according to your health care provider's instructions. You or your caregiver should be trained by a health care provider before injecting enfuvirtide. Before using the medicine, make sure you understand the instructions for preparing and injecting enfuvirtide that come with the medicine. If you (or your caregiver) do not understand the instructions or are having a hard time mixing or injecting enfuvirtide, talk to your health care provider.

Mixing Enfuviritide

  • Use the syringes provided to prepare enfuviritude for injection. Do not use the same syringe to both mix and inject enfuvirtide. Do not mix other medicines in the same syringe with enfuvirtide. If enfuvirtide is foamy or jelled after mixing, give it more time to dissolve. Do not inject enfuvirtide if you see particles floating in the vial after the medicine has been mixed.

Injecting Enfuviritide

  • Enfuvirtide must be injected. The medicine will not work if it is swallowed. Inject enfuvirtide under the skin in the upper arm, upper leg, or stomach 2 times a day. Do not inject enfuvirtide in the same area as you did the time before. Do not inject enfuvirtide into the following areas: near the elbow, knee, groin, or lower or inner buttocks; directly over a blood vessel; around the belly button, scar tissue, a bruise, a mole, a surgical scar, a tattoo, or a burn site; or where there is a reaction at an injection site.
  • After injecting enfuvirtide, safely dispose of the used syringes in a special container called a sharps container. Your health care provider or pharmacist can give you a sharps container. Do not place used syringes in a trash can.

Enfuvirtide can be taken with or without food.

Always take enfuvirtide in combination with other HIV medicines.

If you take too much enfuvirtide, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.

For more information on how to take enfuvirtide, see the FDA drug label from DailyMed. (DailyMed is a federal website that includes the most recent drug labels submitted to FDA.)

What Should I Do If I Forget A Dose?

If you miss a dose of enfuvirtide, take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take 2 doses at the same time to make up for a missed dose.

What Side Effects Can Enfuvirtide Cause?

Enfuvirtide may cause side effects. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the AIDSinfo fact sheet on HIV Medicines and Side Effects for more information.

Some side effects of enfuvirtide can be serious. Serious side effects of enfuvirtide include infected injection sites, severe allergic reaction, and possibly pneumonia. (See the WARNING box above.)

Other possible side effects of enfuvirtide include:

  • Injection site reactions, including itching, swelling, redness, pain or tenderness, hardened skin, or bumps. If the injection site reaction is severe or you have signs of infection at an injection site (oozing, increasing heat, swelling, redness, or pain), contact your health care provider right away.
  • Shooting nerve pain or tingling that lasts up to 6 months. This is likely caused by injecting enfuvirtide close to large nerves or near joints. (This side effect has been reported with use of the Biojector 2000 needle-free device to inject enfuvirtide.)
  • Bruising and/or collection of blood under the skin. (This side effect has also been reported with use of the Biojector 2000 needle-free device.)
  • Changes in your immune system (called immune reconstitution inflammatory syndrome or IRIS). IRIS is a condition that sometimes occurs when the immune system begins to recover after treatment with an HIV medicine. As the immune system gets stronger, it may have an increased response to a previously hidden infection.

Tell your health care provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of enfuvirtide. To learn more about possible side effects of enfuvirtide, read the drug label or package insert or talk to your health care provider or pharmacist.

You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online.

How Should Enfuvirtide Be Stored?

  • Store unmixed enfuvirtide powder vials at room temperature, 59°F to 86°F (15°C to 30°C). If you cannot store unmixed enfuvirtide powder at room temperature, keep it refrigerated, 36°F to 46°F (2°C to 8°C).
  • Store the sterile water vials at room temperature, 59°F to 86°F (15°C to 30°C).
  • Store the mixed enfuvirtide solution in the original vial and keep it refrigerated at 36°F to 46°F (2°C to 8°C). Use the mixed enfuvirtide solution within 24 hours.
  • Do not use enfuvirtide or sterile water after the expiration date on the vials.
  • Do not use enfuvirtide if the original seal on the convenience kit or any of the kit's components are broken or missing.
  • Throw away enfuvirtide that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
  • Keep enfuvirtide and all medicines out of reach of children.

Where Can I Find More Information About Enfuvirtide?

More information about enfuvirtide is available:

Manufacturer Information

Hoffman-La Roche
Main number: 866-422-2377
Patient assistance: 877-436-3683

The above Patient Version drug summary is based on the following FDA label(s): Kit.

[Note from TheBody: This article was originally published by AIDSinfo on July 12, 2018. We have cross-posted it with their permission.]