Note: This document contains side effect information about enfuvirtide. Some dosage forms listed on this page may not apply to the brand name Fuzeon.

Applies to enfuvirtide: subcutaneous powder for solution.

Serious side effects of Fuzeon

Along with its needed effects, enfuvirtide (the active ingredient contained in Fuzeon) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking enfuvirtide:

More common

• Awkwardness
• burning, numbness, tingling, or painful sensations or weakness in the arms, hands, legs, or feet
• cough
• headache
• pain or tenderness around the eyes and cheekbones
• stuffy or runny nose
• tightness of the chest
• troubled breathing
• unsteadiness

Less common

• Bloating
• chills
• constipation
• dark urine
• dry or itching eyes
• excessive tearing
• eye discharge
• fast heartbeat
• fever
• indigestion
• itching, pain, redness, swelling, tenderness, or warmth on the skin at the injection site
• loss of appetite
• lump or growth on the skin
• nausea
• pains in the stomach, side, or abdomen, possibly radiating to the back
• redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
• swollen, painful, or tender lymph glands in the neck, armpit, or groin
• vomiting
• yellow eyes or skin

Rare

• Difficulty in swallowing
• skin itching, rash, or redness
• swelling of the face, throat, or tongue

Incidence not known

• Black, tarry stools
• bleeding gums
• blood in the urine or stools
• chest pain
• decreased frequency or amount of urine
• inability to move the arms and legs
• increased blood pressure
• increased thirst
• lower back or side pain
• painful or difficult urination
• pale skin
• pinpoint red spots on the skin
• sneezing
• sore throat
• sudden numbness and weakness in the arms and legs
• swelling of the face, fingers, lower legs
• ulcers, sores, or white spots in the mouth
• unusual bleeding or bruising
• unusual tiredness or weakness
• weight gain

Other side effects of Fuzeon

Some side effects of enfuvirtide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Abnormal growth filled with fluid or semisolid material
• bruising
• burning or stinging of the skin
• decreased appetite
• diarrhea
• discouragement
• dry mouth
• fear
• feeling sad or empty
• hard lump
• irritability
• lack or loss of strength
• large, flat, blue or purplish patches in the skin
• muscle pain
• nervousness
• painful cold sores or blisters on the lips, nose, eyes, or genitals
• small lumps under the skin
• trouble concentrating
• trouble sleeping
• unusually warm skin
• weight loss

Less common

• Bad, unusual, or unpleasant (after) taste
• burning, itching, and pain in hairy areas
• change in taste
• general feeling of discomfort or illness
• joint pain
• pus at the hair root
• stomach pain

For Healthcare Professionals

Applies to enfuvirtide: subcutaneous kit, subcutaneous powder for injection.

General

In general, the most common side effects in patients receiving enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included injection site reactions, diarrhea, nausea, and fatigue.^[Ref]

Local

Local side effects have been reported in 98% of patients and have included pain/discomfort at the injection site (96%), induration (90%), erythema (91%), nodules and cysts (80%), pruritus (65%), ecchymosis (52%), injection site infection (including abscess and cellulitis, 1.7%), minor local bleeding, injection site reactions, injection site mass, injection site inflammation, and injection site edema. The administration of enfuvirtide (the active ingredient contained in Fuzeon) using the Biojector (R) 2000 needle-free device has been associated with hematomas, bruising, tenderness, and swelling. At least one case of localized amyloidosis at the site of enfuvirtide injection has been reported.^[Ref]

Gastrointestinal

Gastrointestinal side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included diarrhea (31.7%), nausea (22.8%), abdominal pain (3.9%), dry mouth (2.1%), pancreatitis (3.0%), abdominal distension, vomiting, flatulence, and oral candidiasis. Constipation, increased amylase, and increased lipase have also been reported; however, causality has not been determined.^[Ref]

Hypersensitivity

Hypersensitivity side effects have included hypersensitivity reactions in less than 1% of patients and in some cases have recurred upon rechallenge. Signs and symptoms of reactions have included rash, fever, nausea, vomiting, chills, rigors, hypotension, elevated liver transaminases, primary immune complex reaction, respiratory distress, glomerulonephritis, and Guillain-Barre syndrome. Worsening of abacavir hypersensitivity reaction has been reported; however, causality has not been established. General allergic reaction (not defined as hypersensitivity reaction) has also been reported.^[Ref]

Metabolic

Metabolic side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) in combination with a background regimen have included decreased weight (6.6%), decreased appetite (3.2%), anorexia (2.3%), and hyperlipemia. Increased triglycerides and hyperglycemia have also been reported; however, causality has not been established.^[Ref]

Nervous system

Nervous system side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included peripheral neuropathy, taste disturbance, sixth nerve palsy and fatal Guillain-Barre syndrome have also been reported; however, causality has not been established. Dizziness, headache, and epidural abscess have also been reported. The administration of enfuvirtide using the Biojector (R) 2000 needle-free device has been associated with neuralgia and/or paresthesia (nerve pain) lasting up to 6 months when injected at sites where large nerves run close to the skin.^[Ref]

Other

Other side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included fatigue (20.2%), herpes simplex (3.5%), influenza-like illness (2.4%), malaise, fever, and chills. Asthenia and sepsis have also been reported; however, causality has not been determined.^[Ref]

Psychiatric

Psychiatric side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included insomnia, depression, anxiety, and suicide attempt; however, causality has not been established. Abnormal thinking and agitation have also been reported.^[Ref]

Respiratory

Respiratory side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included cough (3.9%), sinusitis (6.0%), bronchitis, nasopharyngitis, and upper respiratory tract infection. Pneumonia (2.7%), including fatalities, pneumopathy, and respiratory distress have also been reported; however, causality has not been determined. Patients should be carefully monitored for symptoms of pneumonia.^[Ref]

Dermatologic

Dermatologic side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included folliculitis (2.4%), dermatitis, pruritus, dry skin, skin papilloma, skin discoloration, and rash (not defined as hypersensitivity reaction).^[Ref]

Musculoskeletal

Musculoskeletal side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included myalgia (2.7%), limb pain (2.9%), and increased creatine phosphokinase (Grade 3, 6.9%; Grade 4, 2.6%). Vertebral osteomyelitis has also been reported.^[Ref]

Ocular

Ocular side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included conjunctivitis (2.0%).^[Ref]

Hematologic

Hematologic side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included eosinophilia (1 to 2 times ULN, 9.1%; greater than 2 times ULN, 1.8%), leukopenia, and anemia. Thrombocytopenia, neutropenia, and lymphadenopathy have also been reported; however, causality has not been established.^[Ref]

Renal

Renal side effects have included glomerulonephritis, tubular necrosis, renal insufficiency, and renal failure (including fatalities); however, causality has not been established.^[Ref]

Hepatic

Hepatic side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included increased ALT (Grade 3, 4.1%; Grade 4, 1.2%). Increased AST, increased GGT, toxic hepatitis, and hepatic steatosis have also been reported; however, causality has not been determined.^[Ref]

Cardiovascular

Cardiovascular side effects associated with enfuvirtide (the active ingredient contained in Fuzeon) and a background regimen have included unstable angina pectoris; however, causality has not been established.^[Ref]

Genitourinary

Genitourinary side effects have included hematuria.^[Ref]

Immunologic

Immunologic side effects have included immune reconstitution syndrome, opportunistic infections, and general infectious diseases. Autoimmune disorders (e.g., Graves' disease, polymyositis, and Guillain-Barre syndrome) have been reported in the setting of immune reconstitution.^[Ref]