Version July 2025
HIV-1 infection, treatment: Note: Gene mutation and antiretroviral (ARV) resistance patterns should be evaluated (refer to https://www.iasusa.org/ for more information) when necessary. Although FDA approved, contemporary use is uncommon secondary to availability of more preferable options. The role in therapy is typically reserved when other options are not available; it is not recommended as initial therapy in patients who are ARV naive (Ref).
Children weighing ≥11 kg and Adolescents:
Weight-directed dosing: SubQ: 2 mg/kg/dose twice daily; maximum dose: 90 mg/dose.
Fixed dosing (weight-band): SubQ:
11 to 15.5 kg: 27 mg twice daily.
15.6 to 20 kg: 36 mg twice daily.
20.1 to 24.5 kg: 45 mg twice daily.
24.6 to 29 kg: 54 mg twice daily.
29.1 to 33.5 kg: 63 mg twice daily.
33.6 to 38 kg: 72 mg twice daily.
38.1 to 42.5 kg: 81 mg twice daily.
≥42.6 kg: 90 mg twice daily.
Children weighing ≥11 kg and Adolescents: No dosage adjustment necessary.
Children weighing ≥11 kg and Adolescents: No dosage adjustment necessary.
(For additional information see "Enfuvirtide: Drug information")
HIV-1 infection, treatment: SubQ: 90 mg twice daily.
No dosage adjustment necessary.
No dosage adjustment necessary (has not been studied).
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
>10%:
Central nervous system: Fatigue (20%), insomnia (11%)
Gastrointestinal: Diarrhea (32%), nausea (23%)
Local: Injection site reaction (98%; may include cyst at injection site, erythema at injection site, induration at injection site, injection site ecchymosis, injection site nodule, injection site pruritus, pain at injection site), injection site infection (children: 11%, adults: 2%)
1% to 10%:
Dermatologic: Folliculitis (2%)
Endocrine & metabolic: Weight loss (7%)
Gastrointestinal: Abdominal pain (4%), decreased appetite (3%), pancreatitis (3%), anorexia (2%), xerostomia (2%)
Hematologic & oncologic: Eosinophilia (2% to 9%)
Hepatic: Increased serum transaminases (4%, grade 4: 1%)
Infection: Infection (4% to 6%), herpes simplex infection (4%)
Neuromuscular & skeletal: Increased creatine phosphokinase (3% to 7%), limb pain (3%), myalgia (3%)
Ophthalmic: Conjunctivitis (2%)
Respiratory: Sinusitis (6%), cough (4%), bacterial pneumonia (3%), flu-like symptoms (2%)
<1%, postmarketing, and/or case reports: Amyloidosis (cutaneous; at the injection site), angina pectoris, anxiety, constipation, depression, dysgeusia, glomerulonephritis, Guillain-Barré syndrome, hyperglycemia; hypersensitivity exacerbation (to abacavir), hypersensitivity reaction (symptoms may include fever, hypotension, increased serum transaminases, nausea, skin rash, vomiting); increased amylase, increased gamma-glutamyl transferase, insomnia, increased serum lipase, increased serum triglycerides, liver steatosis, lymphadenopathy, neutropenia, peripheral neuropathy, pulmonary disease, renal failure, renal insufficiency, renal tubular necrosis, respiratory distress, sepsis, sixth nerve palsy, suicidal tendencies, thrombocytopenia, toxic hepatitis, weakness
Hypersensitivity to enfuvirtide or any component of the formulation
Concerns related to adverse effects:
• Hypersensitivity reactions: May cause hypersensitivity reactions (symptoms may include rash, fever, nausea, vomiting, chills, rigors, hypotension, and/or elevated liver transaminases). Additionally, immune mediated reactions (eg, glomerulonephritis, Guillain-Barré syndrome, primary immune complex reaction, respiratory distress) have been reported. Discontinue therapy immediately if systemic reactions occur; do not rechallenge patient.
• Immune reconstitution syndrome: Patients may develop immune reconstitution syndrome resulting in the occurrence of an inflammatory response to an indolent or residual opportunistic infection during initial HIV treatment or activation of autoimmune disorders (eg, Graves’ disease, polymyositis, Guillain-Barré syndrome) later in therapy; further evaluation and treatment may be required.
• Injection site reactions: Local injection site reactions are common. Administration using a needle-free device has been associated with nerve pain (including neuralgia and/or paresthesia lasting up to 6 months), bruising, and hematomas when administered at sites where large nerves are close to the skin; only administer medication in recommended sites.
• Pneumonia: Monitor closely for signs/symptoms of pneumonia; associated with an increased incidence during clinical trials, particularly in patients with a low CD4 cell count, high initial viral load, IV drug use, smoking, or a history of lung disease.
Disease-related concerns:
• Bleeding disorders: Use with caution in patients with coagulation disorders (eg, hemophilia) or receiving anticoagulants; increased risk of bleeding at injection site.
• Appropriate use: Use is not recommended in antiretroviral therapy-naive patients.
Genentech will discontinue all marketing and commercial distribution of Fuzeon in the United States on February 28, 2025. Further information is available at https://www.gene.com/media/statements/ps_081924.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Subcutaneous:
Fuzeon: 90 mg (1 ea)
No
Solution (reconstituted) (Fuzeon Subcutaneous)
90 mg (per each): $71.71
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Kit, Subcutaneous:
Fuzeon: 90 mg [DSC]
SubQ: Bring refrigerated reconstituted vials to room temperature before injection and visually inspect vial again; solution should be clear, colorless, and without particulate matter or bubbles.
Inject SubQ into upper arm, abdomen, or anterior thigh. Do not inject IM (severity of reactions is increased). Do not inject into skin abnormalities including directly over a blood vessel, into moles, bruises, scar tissue, near the navel, surgical scars, burn sites, or tattoos. Do not inject in or near sites where large nerves are close to the skin including near the elbow, knee, groin, and inferior or medial sections of the buttocks. Rotate injection site (ie, give injections at a site different from the preceding injection site); do not inject into any site where an injection site reaction is present. After injection, apply heat or ice to injection site or gently massage area to better disperse the dose, to minimize local injection reactions (Ref); discard unused portion of the vial (vial is for single use only).
SubQ: Inject subcutaneously into upper arm, abdomen, or anterior thigh. Do not inject into moles, the navel, over a blood vessel or skin abnormalities such as scar tissue, surgical scars, bruises, tattoos, or burn sites. In addition, do not inject in or near sites where large nerves are close to the skin including the elbow, knee, groin, or buttocks. Rotate injection site, give injections at a site different from the preceding injection site; do not inject into any site where an injection site reaction is evident. Bioequivalence was found to be similar in a study comparing standard administration using a needle versus a needle-free device (Ref).
Store intact vials at 25°C (77°F); excursions are permitted between 15°C and 30°C (59°F and 86°F). Store reconstituted solution in the original vial at 2°C to 8°C (36°F to 46°F); use within 24 hours. Vials are for single use only; discard unused portion.
Treatment of HIV-1 infection in combination with other antiretroviral agents in treatment-experienced patients who are failing current antiretroviral therapy (FDA approved in pediatric patients weighing ≥11 kg and adults). Note: HIV regimens consisting of 3 antiretroviral agents from at least 2 classes are strongly recommended. Although FDA approved, contemporary use is uncommon secondary to availability of more preferable options. It is not recommended as initial therapy in patients who are antiretroviral naive (HHS [pediatric] 2018).
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program
Atidarsagene Autotemcel: Antiretroviral Agents may decrease therapeutic effects of Atidarsagene Autotemcel. Risk X: Avoid
Betibeglogene Autotemcel: Antiretroviral Agents may decrease therapeutic effects of Betibeglogene Autotemcel. Risk X: Avoid
Elivaldogene Autotemcel: Antiretroviral Agents may decrease therapeutic effects of Elivaldogene Autotemcel. Management: Avoid use of antiretroviral medications for at least one month, or for the amount of time required for elimination of the retroviral medication, prior to stem cell mobilization and until the all apheresis cycles are finished Risk X: Avoid
Lovotibeglogene Autotemcel: Antiretroviral Agents may decrease therapeutic effects of Lovotibeglogene Autotemcel. Risk X: Avoid
Orlistat: May decrease serum concentration of Antiretroviral Agents. Risk C: Monitor
Contraception is not required to initiate or continue antiretroviral therapy.
Enfuvirtide is not recommended (except in special circumstances) for patients with HIV who are not yet pregnant but are trying to conceive.
Maximum viral suppression sustained below the limits of detection prior to conception is recommended for all persons with HIV who are planning a pregnancy. Prior to pregnancy, select or make changes to a specific antiretroviral regimen as part of a shared decision-making process. In most cases, recommendations based on data obtained from cisgender women can be applied to transgender and gender diverse people assigned female sex at birth.
Health care providers caring for couples planning a pregnancy when one or both partners are diagnosed with HIV may contact the National Perinatal HIV Hotline (1-888-448-8765) for clinical consultation (HHS [perinatal] 2024).
Enfuvirtide has minimal to low transfer across the human placenta.
Outcome data specific to enfuvirtide use in pregnancy are no longer being reviewed and updated in the Health and Humans Services (HHS) Perinatal Guidelines. Enfuvirtide is not recommended as initial therapy for pregnant patients with HIV; enfuvirtide is not recommended (except in special circumstances) in pregnant patients who have had antiretroviral therapy (ART) therapy in the past but are restarting, or who require a new ART regimen (due to poor tolerance or poor virologic response of current regimen). Patients who become pregnant while taking enfuvirtide may continue if viral suppression is effective and the regimen is well tolerated.
Maternal antiretroviral therapy (ART) may be associated with adverse pregnancy outcomes, including preterm birth, low birth weight, and small for gestational age infants. High viral loads are also associated with adverse outcomes, including preterm birth and pregnancy loss. Treatment improves the health of the pregnant patient and reduces the risk of perinatal transmission. Do not withhold appropriate maternal ART due to concerns for adverse neonatal outcomes. Closely monitor for pregnancy complications. Document in utero ART exposure in the long-term medical record of a child born without HIV; evaluate for potential metabolic dysfunction if significant organ system abnormalities of unknown etiology (particularly of the CNS or heart) develop.
ART is recommended for all pregnant people with HIV to maximize their health, maintain the viral load below the limit of an ultrasensitive assay detection, and reduce the risk of perinatal transmission. Start ART prior to conception or as soon as possible during pregnancy. During pregnancy, select or make changes to a specific antiretroviral regimen as part of a shared decision-making process. Patients on fully suppressive regimens prior to pregnancy generally may continue the same regimen considering known pregnancy outcomes and pharmacokinetic data. Monitor pregnant patients more frequently than nonpregnant patients. ART initiated during pregnancy can be modified after delivery. In most cases, recommendations based on data obtained from cisgender women can be applied to transgender and gender diverse people assigned female sex at birth.
Data collection to monitor pregnancy and infant outcomes following exposure to ART is ongoing. Enroll all patients exposed to antiretroviral medications as early in pregnancy as possible in the Antiretroviral Pregnancy Registry (1-800-258-4263).
Health care providers caring for pregnant patients with HIV infection and their infants may contact the National Perinatal HIV Hotline (1-888-448-8765) for clinical consultation (HHS [perinatal] 2024).
HIV: General recommendations: Management of HIV infection requires extensive monitoring; refer to current guidelines (https://clinicalinfo.hiv.gov/en/guidelines) for additional guidance. Antiretroviral drug-resistance testing is recommended before initiation of therapy in treatment-naive patients. After initiation of or change in antiretroviral therapy regimen, pediatric patients should be evaluated for clinical adverse effects and treatment adherence at 1 to 2 weeks, and laboratory testing for drug toxicity should occur at 2 to 4 weeks; monitor for therapy adherence, effectiveness, and toxicities every 3 to 4 months.
Drug-specific monitoring: Frequency may vary based on several factors including age, concomitant therapy, and clinical response; refer to current guidelines for additional information.
Monitor injection site for cellulitis (more common in pediatric patients) and sign/symptoms of hypersensitivity reactions; signs/symptoms of bacterial pneumonia.
Binds to the first heptad-repeat (HR1) in the gp41 subunit of the viral envelope glycoprotein. Inhibits the fusion of HIV-1 virus with CD4 cells by blocking the conformational change in gp41 required for membrane fusion and entry into CD4 cells
Absorption: SubQ: Absorption is comparable when injected into abdomen, arm, or thigh
Distribution: Vd: 5.5 ± 1.1 L ; CSF concentrations (2-18 hours after administration; n=4): nondetectable (<0.025 mcg/mL)
Protein binding: 92%; primarily to albumin, but also to alpha-1 acid glycoprotein (to a lesser extent)
Metabolism: Expected to undergo catabolism via peptidases and proteinases in the liver and kidneys to amino acids; amino acids would then be recycled in the body pool. A deaminated metabolite (with 20% activity compared to parent drug) was formed via hydrolysis during in vitro human microsomal and hepatocyte studies.
Bioavailability: SubQ: Absolute: 84.3% ± 15.5%; Note: Bioequivalence was found to be similar in a study comparing standard administration using a needle versus a needle-free device.
Half-life elimination: 3.8 ± 0.6 hours
Time to peak: SubQ: Single dose: Median: 8 hours (range: 3 to 12 hours); Multiple dosing: Median: 4 hours (range: 4 to 8 hours)
