Pronunciation:
fos-tem-sa-vir
Trade Name(s)
Ther. Class.
Pharm. Class.
GP120 attachment inhibitors
Human immunodeficiency virus type 1 (HIV-1) infection in heavily treatment-experienced patients with multidrug-resistant HIV-1 infection who have failed their current antiretroviral regimen due to resistance, intolerance, or safety considerations (in combination with other antiretroviral agents).
Fostemsavir is a prodrug that is hydrolyzed to the active form, temsavir. Temsavir binds directly to the gp120 subunit within the HIV-1 envelope glycoprotein gp160 and selectively prevents attachment of the virus to the CD4 receptors on cells.
Therapeutic Effect(s):
Reduction in viral load.
Absorption: 27% of temsavir absorbed following oral administration; absorption ↑ with high-fat meal.
Distribution: Moderately distributed to extravascular tissues.
Metabolism and Excretion: Fostemsavir is a prodrug that is hydrolyzed to the active form, temsavir. Temsavir undergoes metabolism to inactive metabolites through the liver via hydrolysis and oxidation (via the CYP3A4 isoenzyme). Primarily excreted in urine (51%, <2% as unchanged drug), with 33% excreted in feces (1% as unchanged drug).
Half-life: 11 hr.
TIME/ACTION PROFILE (plasma concentrations)
ROUTE | ONSET | PEAK | DURATION |
---|---|---|---|
PO | Rapid | 2 hr | 12 hr |
Contraindicated in:
Use Cautiously in:
CV: QT interval prolongation
Derm: rash
Endo: Graves' disease, hyperglycemia
GI: nausea, ↑ lipase, ↑ liver enzymes, abdominal pain, autoimmune hepatitis, diarrhea, dyspepsia, hyperbilirubinemia, vomiting
GU: ↑ serum creatinine
Hemat: anemia, neutropenia
Metabolic: hypercholesterolemia, hyperuricemia
MS: ↑ creatine kinase, polymyositis
Neuro: Guillain-Barré syndrome, headache, insomnia, sedation
Misc: fatigue, immune reconstitution syndrome
* CAPITALS indicate life-threatening.
Underline indicate most frequent.
Drug-Drug
Strong CYP3A4 inducers, including carbamazepine, enzalutamide, mitotane, phenytoin, and rifampin may ↓ levels and lead to loss of virologic response; concurrent use contraindicated.
Drug-Natural Products:
St. John's wort may ↓ levels and lead to loss of virologic response; concurrent use contraindicated.
PO (Adults): 600 mg twice daily.
Extended-release tablets: 600 mg
Lab Test Considerations:
Monitor viral load and CD4 cell count regularly during therapy.
Immune reconstitution syndrome may trigger opportunistic infections or autoimmune disorders. Notify health care professional if symptoms (signs and symptoms of an infection or inflammation) occur.