Enfuvirtide

Reconstitute with 1.1 mL sterile water for inj. Tap the vial for 10 seconds and gently roll between the hands; avoid foaming and ensure contact with diluent. Allow the vial to stand until complete dissolution. May require up to 45 minutes to form a solution; if the solution is foamy or jelled, allow it to stand for a longer period of time.

Hypersensitivity.

Patient with bleeding disorders (e.g. haemophilia), chronic hepatitis B or C, severe immune deficiency; risk factors for pneumonia (including low CD4 count, history of lung disease, high initial viral load, IV drug use, and smoking). Not recommended for use in antiretroviral therapy-naive patients. HIV-infected mothers are advised not to breastfeed to prevent the risk of postnatal transmission of HIV and to avoid any potential undesirable effects in breastfed infants. Hepatic and moderate to severe renal impairment. Children. Pregnancy and lactation.

Significant: Hypersensitivity reactions (e.g. nausea, vomiting, rash, fever, chills, rigors, hypotension, and/or elevated liver enzymes); immune mediated reactions (e.g. glomerulonephritis, Guillain-Barre syndrome, primary immune complex reaction, respiratory distress); immune reconstitution syndrome causing an inflammatory response to an indolent or residual opportunistic infection (e.g. Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia, tuberculosis) or activation of an autoimmune disorder (e.g. Graves' disease, polymyositis); local inj site reactions (e.g. pain, erythema, induration, nodules and cysts, pruritus, ecchymosis, bruising, haematomas); pneumonia, osteonecrosis; increased risk of post-injection bleeding (particularly in patients with bleeding disorders).
Blood and lymphatic system disorders: Lymphadenopathy, eosinophilia.
Ear and labyrinth disorders: Vertigo.
Eye disorders: Conjunctivitis.
Gastrointestinal disorders: Abdominal pain, diarrhoea, pancreatitis, gastro-oesophageal reflux disease.
General disorders and administration site conditions: Fatigue, asthenia.
Infections and infestations: Sinusitis, skin papilloma, influenza, ear infection.
Investigations: Decreased weight.
Metabolism and nutrition disorders: Anorexia, hypertriglyceridaemia, diabetes mellitus.
Musculoskeletal and connective tissue disorders: Myalgia.
Nervous system disorders: Peripheral neuropathy, hypoaesthesia, disturbance in attention, tremor.
Psychiatric disorders: Insomnia, anxiety, irritability.
Renal and urinary disorders: Nephrolithiasis, haematuria.
Respiratory, thoracic and mediastinal disorders: Nasal congestion, cough.
Skin and subcutaneous tissue disorders: Dry skin, seborrhoeic eczema, erythema, acne.
Potentially Fatal: Increased risk for severe hepatic side effects (particularly in patients with chronic hepatitis B or C).

Monitor viral load, CD4 count, and paediatric weight (periodically). Assess for signs and symptoms of pneumonia, hypersensitivity and inj site reactions.

Increased risk of injection site bleeding when concomitantly received with anticoagulants.

May cause false-positive HIV test with the anti-HIV ELISA test in non-HIV infected patients.

Description:
Mechanism of Action: Enfuvirtide is an antiretroviral drug classified as an HIV fusion inhibitor. It binds to the 1st heptad-repeat (HR1) in the envelope glycoprotein 41 (gp41), thereby blocking the conformational changes in the HIV-1 glycoprotein required for the fusion of viral and cellular membranes. This action prevents the viral genome from entering the target cell.
Pharmacokinetics:
Absorption: Almost completely absorbed following SC inj (comparable when given via the abdomen, arm, or thigh). Bioavailability: 84.3 ± 15.5 %. Time to peak plasma concentration (median): Single dose: 8 hours (range: 3-12 hours); multiple dosing: 4 hours (range: 4-8 hours).
Distribution: Crosses the placenta (small amounts). Plasma protein binding: 92%, mainly to albumin but also to a lesser extent to α-1 acid glycoprotein.
Metabolism: Metabolised in the liver and kidneys via catabolism by peptidases and proteinases into amino acids, with subsequent recycling of these amino acids in the body pool; undergoes hydrolysis to form a deaminated metabolite.
Excretion: Elimination half-life: 3.8 ± 0.6 hours.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 16130199, Enfuvirtide. https://pubchem.ncbi.nlm.nih.gov/compound/Enfuvirtide. Accessed Apr. 28, 2025.

Intact vials: Store between 15-30°C. Reconstituted solution (in the original vial): Store between 2-8°C for 24 hours.

Antivirals

J05AX07 - enfuvirtide ; Belongs to the class of other antivirals. Used as a direct acting antiviral in the systemic treatment of viral infections.

Brayfield A, Cadart C (eds). Enfuvirtide. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 03/04/2025.

Enfuvirtide. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 03/04/2025.

Enfuvirtide. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 03/04/2025.

Fuzeon (Genentech, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 03/04/2025.

Fuzeon 90 mg/mL Powder and Solvent for Solution for Injection (Roche Products Limited). MHRA. https://products.mhra.gov.uk. Accessed 03/04/2025.

Joint Formulary Committee. Enfuvirtide. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 03/04/2025.

Paediatric Formulary Committee. Enfuvirtide. BNF for Children [online]. London. BMJ Group, Pharmaceutical Press, and RCPCH Publications. https://www.medicinescomplete.com. Accessed 03/04/2025.