Foscarnet

Foscarnet

File:Fascarnet.png
Clinical data
Pregnancy category	B3 (Au), C (U.S.)
Routes of administration	Intravenous
ATC code	J05AD01 (WHO)
Legal status
Legal status	℞-only (U.S.), POM (UK)
Pharmacokinetic data
Bioavailability	NA
Protein binding	14-17%
Elimination half-life	3.3-6.8 hours
Identifiers
IUPAC name phosphonomethanoic acid
CAS Number	63585-09-1
PubChem CID	3415
DrugBank	APRD00669
E number	{{#property:P628}}
ECHA InfoCard	{{#property:P2566}}
Chemical and physical data
Formula	CH3O5P
Molar mass	126.005 g/mol 300.1 g/mol (foscarnet trisodium hexahydrate)

Foscarnet is the conjugate base of the chemical compound with the formula HO₂CPO₃H₂. This phosphonic acid derivative is (marketed by AstraZeneca as foscarnet sodium under the trade name Foscavir®) is an antiviral medication used to treat herpes viruses, including cytomegalovirus (CMV) and herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). It is particularly used to treat CMV retinitis.

Mechanism of action

Foscarnet is a structural mimic of the anion pyrophosphate that selectively inhibits the pyrophosphate binding site on viral DNA polymerases at concentrations that do not affect human DNA polymerases. Because foscarnet is not activated by thymidine kinase, it maintains activity in some viruses which have lost thymidine kinase activity to gain resistance to aciclovir or ganciclovir. Therefore, foscarnet is often used in aciclovir- or ganciclovir-resistant disease. However, acyclovir or ganciclovir resistant mutants with alterations in viral DNA polymerase may be resistant to foscarnet.

Administration

Intravenous only

Side effects

• Renal failure
• Decreased calcium levels