Enfuvirtide treats HIV infection. Do not skip any doses as this may make it more difficult to treat HIV.

Enfuvirtide Overview

Reviewed: September 24, 2012

Enfuvirtide is a prescription medication used to treat human immunodeficiency virus (HIV). It is always used in combination with other medications. Enfuvirtide belongs to a group of drugs called HIV fusion inhibitors. It works by stopping HIV from entering human cells. HIV must enter human cells in order to replicate.

This medication comes in an injectable form. It is injected just under the skin of the upper arm, stomach area, or thigh, twice daily.

Common side effects of enfuvirtide include redness, pain, and other effects at the injection site. Other common side effects include weight loss, sinus infection and dizziness. Do not drive a car or operate machinery until you know how this medication affects you.


How was your experience with Enfuvirtide?

First, a little about yourself

Tell us about yourself in a few words?

What tips would you provide a friend before taking Enfuvirtide?

What are you taking Enfuvirtide for?

Choose one
  • Other
  • Acquired Immunodeficiency Syndrome
  • Hiv Infections

How long have you been taking it?

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  • Less than a week
  • A couple weeks
  • A month or so
  • A few months
  • A year or so
  • Two years or more

How well did Enfuvirtide work for you?

Did you experience many side effects while taking this drug?

How likely would you be to recommend Enfuvirtide to a friend?

Enfuvirtide Cautionary Labels


Uses of Enfuvirtide

Enfuvirtide is a prescription medication used to treat human immunodeficiency virus (HIV). It is always used in combination with other medications.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Enfuvirtide Brand Names

Enfuvirtide may be found in some form under the following brand names:

Enfuvirtide Drug Class

Enfuvirtide is part of the drug class:

Side Effects of Enfuvirtide

Injection Site Reactions

Enfuvirtide causes injection site reactions. Almost all people get injection site reactions with enfuvirtide. Reactions are usually mild to moderate but occasionally may be severe. Reactions on the skin where enfuvirtide is injected include:

  • itching
  • swelling
  • redness
  • pain or tenderness
  • hardened skin
  • bumps

These reactions generally happen within the first week of enfuvirtide treatment and usually happen again as you keep using enfuvirtide. A reaction at one skin injection site usually lasts for less than 7 days.

Injection site reactions may be worse when injections are given again in the same place on the body or when the injection is given deeper than it should be (for example, into the muscle).

If you are worried about the reaction you are having, call your healthcare provider to help you decide if you need medical care. If the injection site reaction you are having is severe, call your healthcare provider right away. If you have an injection site reaction, you can discuss with your healthcare provider ways to help the symptoms.

An injection site can get infected. It is important to follow the enfuvirtide Injection Instructions that come with your medicine to lower your chances of getting an injection site infection. Call your healthcare provider right away if there are signs of infection at the injection site such as oozing, increasing heat, swelling, redness or pain.

Injection using Biojector 2000

Shooting nerve pain and tingling lasting up to 6 months from injecting close to large nerves or near joints, and bruising and/or collections of blood under the skin have been reported with use of the Biojector 2000 needle-free device to inject enfuvirtide. If you are taking any blood thinners, or have hemophilia or any other bleeding disorder, you may be at higher risk of bruising or bleeding after using the Biojector.


Patients with HIV get bacterial pneumonia more often than patients without HIV. Patients taking enfuvirtide with other HIV medicines may get bacterial pneumonia more often than patients not receiving enfuvirtide. It is unclear if this is related to the use of enfuvirtide. You should contact your healthcare provider right away if you have a cough, fever or trouble breathing. Patients are more likely to get bacterial pneumonia if they had a low number of CD4 cells, increased amount of HIV in the blood, intravenous (injected into the vein) drug use, smoking or had experienced lung disease in the past. It is unclear if pneumonia is related to enfuvirtide.

Allergic reactions

Enfuvirtide can cause serious allergic reactions. Symptoms of a serious allergic reaction with enfuvirtide can include:

  • trouble breathing
  • fever with vomiting and a skin rash
  • blood in your urine
  • swelling of your feet

Call your healthcare provider right away if you get any of these symptoms.

Other side effects

The following side effects were seen more often in patients using enfuvirtide with their other anti-HIV medicines than in patients not using enfuvirtide with their other anti-HIV medicines:

  • pain and numbness in feet or legs
  • loss of sleep
  • depression
  • decreased appetite
  • sinus problems
  • enlarged lymph nodes
  • weight decrease
  • weakness or loss of strength
  • muscle pain
  • constipation
  • pancreas problems

These are not all the side effects of enfuvirtide. For more information, ask your healthcare provider or pharmacist.

If you have questions about side effects, ask your healthcare provider. Report any new or continuing symptoms to your healthcare provider. Your healthcare provider will tell you what to do and may be able to help you with these side effects.

Enfuvirtide Interactions

Tell your healthcare provider about all the medicines you use, including prescription and non-prescription medicines, vitamins, and herbal supplements. Enfuvirtide has not been tested with all medicines. 

Enfuvirtide does not affect other anti-HIV medicines or the medicine rifampin (also known as rifampicin, Rifadin or Rimactane). You can take enfuvirtide at the same times or at different times than your other anti-HIV medicines.

Enfuvirtide Precautions

  • Do not use enfuvirtide if you are allergic to any of the ingredients in it.
  • Avoid doing anything that can spread HIV infection since enfuvirtide does not stop you from passing the HIV infection to others.
    • Do not share needles or other injection equipment.
    • Do not share personal items that can have blood or body fluids on them, like toothbrushes or razor blades.
    • Do not have any kind of sex without protection. Always practice safer sex by using a latex or polyurethane condom or other barrier method to reduce the chance of sexual contact with semen, vaginal secretions or blood.
  • Do not drive or operate heavy machinery if enfuvirtide makes you feel dizzy.


Enfuvirtide Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of enfuvirtide there are no specific foods that you must exclude from your diet when receiving this medication.


Inform MD

Tell your healthcare provider:

  • if you are pregnant or breastfeeding
  • about all your medical conditions
  • about all the medicines you use, including prescription and non-prescription medicines, vitamins, and herbal supplements

Enfuvirtide and Pregnancy

Tell your healthcare provder if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Enfuvirtide falls into category B. There are no well-done studies that have been done in humans with but in animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.

Pregnancy Registry. There is a pregnancy registry for women who take antiviral medicines during pregnancy. The purpose of this registry is to collect information about the health of you and your baby. Talk with your healthcare provider about how you can take part in this registry.

Enfuvirtide and Lactation

Tell your healthcare provider if you are breastfeeding. 

It is not known if enfuvirtide can be passed to your baby in your breast milk and whether it could harm your baby. Also, mothers with HIV-1 should not breastfeed because HIV-1 can be passed to the baby in the breast milk.

Enfuvirtide Usage

Before you use enfuvirtide, make sure you understand all of the information on enfuvirtide and the enfuvirtide Injection Instructions that come with this medication. You or your caregiver should be trained by a healthcare provider before injecting it. If you do not understand all the information or are having a hard time mixing or injecting enfuvirtide, talk with your healthcare provider.

  • Use enfuvirtide with other anti-HIV medicines. You can take enfuvirtide at the same time or at a different time than your other anti-HIV medicines.
  • Do not use enfuvirtide as your only anti-HIV medicine.
  • Enfuvirtide must be injected. Enfuvirtide does not work if the medicine is swallowed.
  • Do not mix other medicines in the same syringe with enfuvirtide.
  • Enfuvirtide is given under the skin by injection (a "shot") in the upper arm, upper leg or stomach two times a day. See the enfuvirtide injection instructions that come with your medicine for step-by-step instructions about how to inject enfuvirtide.
  • 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, the lower or inner buttocks, directly over a blood vessel, around the navel (belly button), scar tissue, a bruise, a mole, a surgical scar, tattoo or burn site, or where there is an injection site reaction.
  • If the enfuvirtide is foamy or jelled, allow more time for it to dissolve. Do not inject enfuvirtide if you see particles floating in the enfuvirtide vial after you mix it up.
  • You can use enfuvirtide whether you have eaten or not. Food does not affect enfuvirtide. However, you must keep taking your other medicines the way you did before.
  • Do not change your dose or stop taking enfuvirtide without first talking with your healthcare provider.
  • See your healthcare provider regularly while using enfuvirtide.
  • When your enfuvirtide supply runs low, be sure to have it refilled. This is very important because the amount of virus in your blood may increase if the medicine is stopped for even a short time. If you miss or skip doses of enfuvirtide, HIV may develop resistance to enfuvirtide and become harder to treat.
  • If you miss a dose of enfuvirtide, take the missed dose as soon as you can and then take your next dose as scheduled. If you have missed a dose of enfuvirtide and it is close to the time when you are supposed to take your next dose, wait and take the next dose as regularly scheduled. Do not take two doses of enfuvirtide at the same time.
  • If you take too much enfuvirtide, call your healthcare provider right away. We do not know what can happen if you take too much enfuvirtide. You will be watched very carefully if you take too much enfuvirtide.
  • It is important that you put your used syringes into a special sharps container after injecting enfuvirtide. Your healthcare provider will give you more instructions about the safe disposal of your used syringes. Do not put them in a trash can. If you do not have a sharps container, call your healthcare provider or pharmacist to get one before using enfuvirtide.

Enfuvirtide Dosage

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

  • your weight
  • your age

The recommended dose of enfuvirtide is 90 mg (1 mL) twice daily.

The recommended dose of enfuvirtide for pediatric patients (6 to 16 years of age) is 2 mg/kg to a maximum dose of 90 mg twice daily.

Enfuvirtide Overdose

If you take too much enfuvirtide, call your healthcare provider right away or seek emergency medical attention.


Other Requirements

  • Enfuvirtide vials not mixed with sterile water can be stored at room temperature (59° to 86°F). enfuvirtide should be refrigerated if it cannot be stored at room temperature.
  • The Sterile Water for Injection (diluent) may be stored at room temperature (59° to 86°F).
  • After enfuvirtide has been mixed with the sterile water, the vial can be stored in a refrigerator for up to 24 hours.
  • Do not use enfuvirtide or sterile water after the expiration date on the vials. Do not keep enfuvirtide that is out of date or that you no longer need.
  • If you have more questions about how to store enfuvirtide, ask your healthcare provider or pharmacist or call 1-877-4-enfuvirtide.