Enfuvirtide
Also known as Fuzeon, T-20
Enfuvirtide is a synthetic 36-amino-acid peptide and was the first HIV fusion inhibitor approved for treating HIV-1 infection. It is reserved for treatment-experienced patients with evidence of viral replication despite ongoing antiretroviral therapy, typically as part of an optimized combination regimen for multidrug-resistant HIV-1. Because it must be reconstituted and injected subcutaneously twice daily, and commonly causes injection site reactions, its use has declined as newer oral antiretroviral classes have become available. It remains a prescription-only specialist therapy.
Reported benefits
- Provides an additional mechanism of action for HIV-1 resistant to other antiretroviral classes
- Can help achieve viral suppression in heavily treatment-experienced patients when combined with an optimized background regimen
- Acts extracellularly, blocking viral entry before infection of the cell occurs
How it works
Enfuvirtide binds to the HR1 region of the HIV-1 envelope glycoprotein gp41 during the viral entry process, preventing the conformational change required for the viral and host cell membranes to fuse. By blocking this fusion step, it prevents HIV-1 from entering and infecting CD4+ T cells, acting at an earlier stage of the viral life cycle than reverse transcriptase or protease inhibitors.
Dosing ranges
| Tier | Dose | Frequency |
|---|---|---|
| Low | 45 mg | twice daily (lower weight-based pediatric reference dose) |
| Moderate | 90 mg | twice daily (standard fixed adult dose) |
| High | 90 mg | twice daily (ceiling dose; not increased further in adults) |
Estimate your dose
Dose estimator
Educational estimate for Enfuvirtide, scaled to body size. Not medical advice.
Read before using
This tool produces a rough, educational estimate by scaling commonly-published research ranges to lean body mass. It is not a prescription, medical advice, or a substitute for a licensed clinician. Most peptides use fixed dosing, not weight-based dosing. Individual needs vary. You are solely responsible for how you use this information.
Mixing & syringe units
Target dose follows the estimate above. Change it there, or edit it directly below.
Reconstitution calculator
How much water to add and how many insulin-syringe units to draw for Enfuvirtide. Educational only.
Draw to this mark
1,800units
= 18 mL for a 90 mg dose
Concentration
5 mg/mL
Doses per vial
0
This dose needs 1,800 units, more than a 100-unit syringe holds. Add more water, split the dose, or use a larger syringe.
A U-100 syringe reads 100 units per mL. This is a reconstitution math helper only, not a prescription or dosing advice. Verify every calculation and consult a qualified healthcare provider.
Possible side effects
Stacking notes
Used only in combination with other antiretroviral agents in treatment-experienced patients with resistant HIV-1; never used as monotherapy.
Common protocols
Common questions
What is Enfuvirtide used for?
Enfuvirtide is a synthetic 36-amino-acid peptide and was the first HIV fusion inhibitor approved for treating HIV-1 infection. It is reserved for treatment-experienced patients with evidence of viral replication despite ongoing antiretroviral therapy, typically as part of an optimized combination regimen for multidrug-resistant HIV-1. Because it must be reconstituted and injected subcutaneously twice daily, and commonly causes injection site reactions, its use has declined as newer oral antiretroviral classes have become available. It remains a prescription-only specialist therapy. Reported benefits include provides an additional mechanism of action for hiv-1 resistant to other antiretroviral classes, can help achieve viral suppression in heavily treatment-experienced patients when combined with an optimized background regimen, acts extracellularly, blocking viral entry before infection of the cell occurs.
What is a typical Enfuvirtide dose?
Reported ranges run 45-90 mg. A low protocol is 45 mg twice daily (lower weight-based pediatric reference dose), and a high protocol is 90 mg twice daily (ceiling dose; not increased further in adults). This is reference information, not a dosing recommendation.
What is the half life of Enfuvirtide?
Approximately 3.8 hours. That is what sets the dosing frequency, and it is why the timing guidance is twice daily, evenly spaced.
How is Enfuvirtide administered?
Subcutaneous: into fat, under the skin. Reconstituted powder injected subcutaneously into the abdomen, thigh, or upper arm; rotate injection sites to reduce nodules.
How long is a Enfuvirtide cycle?
Continuous twice-daily injections as part of ongoing combination antiretroviral therapy on, followed by Not discontinued while viral suppression is needed; stopping without a fully suppressive replacement regimen risks viral rebound and resistance off. Adult dosing is fixed at 90 mg twice daily regardless of body weight above the pediatric threshold; it is not titrated upward for dose-response.
What are the side effects of Enfuvirtide?
Reported side effects include injection site reactions (pain, redness, nodules, induration) in most patients, increased rate of bacterial pneumonia observed in clinical trials, hypersensitivity reactions, occasionally severe, peripheral neuropathy. Evidence level for this compound is well studied.
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Educational use only, not medical advice. This profile is provided for research and educational purposes. Enfuvirtide may be a research compound or a prescription medication; nothing here is intended to diagnose, treat, cure, or prevent any disease. Dosing figures reflect commonly-published research ranges, not a prescription. Consult a qualified healthcare provider before making any health decision. Read the full disclaimer →