Fostemsavir
HIV Infections
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Drug Status
Government Approvals
US(FDA)
WHO Essential Medicine
NO
Known Teratogen
No
Pharmaceutical Class
NA
Controlled Drug Substance
No
Fostemsavir
Summary
Fostemsavir is used to treat HIV-1 infection in adults who have multi-drug resistant HIV-1. It's used in combination with other antiretroviral medications when the current regimen isn't working due to resistance, intolerance, or safety concerns.
Fostemsavir is a prodrug that turns into its active form, temsavir, in the body. Temsavir binds to a protein on the HIV-1 virus, preventing it from attaching to human cells. This blocks the virus from entering and infecting the cells, reducing the amount of virus in the body.
The usual dose for adults is one 600 mg tablet taken orally twice daily. It can be taken with or without food, and it's important to take it at the same times each day.
Common side effects of Fostemsavir include nausea, diarrhea, headache, abdominal pain, and tiredness. Serious adverse effects can include immune reconstitution syndrome, QT interval prolongation, and liver enzyme elevations.
Key warnings include the risk of immune reconstitution syndrome, QT interval prolongation, and liver enzyme elevations, especially in patients with hepatitis B or C co-infection. It's contraindicated in people with hypersensitivity to Fostemsavir or its components and in combination with strong CYP3A inducers, which can reduce its effectiveness.
Indications and Purpose
How does Fostemsavir work?
Fostemsavir is an HIV attachment inhibitor that works by binding to the gp120 protein on the HIV-1 virus. This prevents the virus from attaching to and entering human cells, thereby reducing the viral load in the blood and helping to control the infection.
Is Fostemsavir effective?
Fostemsavir has been shown to be effective in reducing HIV-1 RNA levels in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection. In clinical trials, it demonstrated a significant reduction in viral load when used in combination with other antiretrovirals.
What is Fostemsavir?
Fostemsavir is used to treat HIV-1 infection in adults who have not responded to other treatments. It works by inhibiting the attachment of the virus to human cells, reducing the amount of HIV in the blood. This helps prevent the progression to AIDS and reduces the risk of HIV-related illnesses.
Directions for Use
For how long do I take Fostemsavir?
Fostemsavir is used as a long-term treatment for HIV-1 infection in adults. It should be taken continuously as prescribed by a healthcare provider, even if the patient feels well, to maintain its effectiveness.
How do I take Fostemsavir?
Take Fostemsavir exactly as prescribed by your doctor, usually one 600 mg tablet twice daily. It can be taken with or without food. Swallow the tablets whole without chewing, crushing, or splitting them. There are no specific food restrictions while taking this medication.
How long does it take for Fostemsavir to start working?
Fostemsavir begins to work within a few days, but it may take several weeks to see a significant reduction in HIV-1 RNA levels. Your doctor will monitor your progress with regular blood tests to assess the effectiveness of the treatment.
How should I store Fostemsavir?
Store Fostemsavir in its original container, tightly closed, at room temperature between 68°F to 77°F (20°C to 25°C). Keep it away from excess heat and moisture, and out of reach of children. Do not store it in the bathroom.
What is the usual dose of Fostemsavir?
The usual daily dose for adults is one 600 mg tablet taken orally twice a day, with or without food. The safety and effectiveness of Fostemsavir in children have not been established, so there is no recommended dose for children.
Warnings and Precautions
Can Fostemsavir be taken safely while breastfeeding?
It is not known if Fostemsavir is present in human breast milk. Breastfeeding is not recommended for individuals with HIV-1 infection due to the risk of transmission and potential adverse effects on the infant. Consult your doctor for personalized advice.
Can Fostemsavir be taken safely while pregnant?
There is insufficient human data on the use of Fostemsavir during pregnancy to assess the risk of birth defects or miscarriage. A pregnancy exposure registry is available to monitor outcomes. Consult your doctor if you are pregnant or planning to become pregnant while taking Fostemsavir.
Can I take Fostemsavir with other prescription drugs?
Significant drug interactions with Fostemsavir include strong CYP3A inducers like rifampin, which can decrease its effectiveness. It may also interact with certain anticonvulsants, antineoplastics, and herbal products like St. John's wort, potentially leading to reduced efficacy or increased side effects.
Is Fostemsavir safe for the elderly?
Elderly patients may be more susceptible to drug-induced QT interval prolongation. Caution should be exercised when administering Fostemsavir to elderly patients due to the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
Who should avoid taking Fostemsavir?
Fostemsavir is contraindicated in patients with hypersensitivity to the drug or its components and those taking strong CYP3A inducers. Warnings include the risk of immune reconstitution syndrome, QTc prolongation, and liver enzyme elevations in patients with hepatitis B or C co-infection.
