Fosamprenavir

Fosamprenavir

Systematic (IUPAC) name
{[(2R,3S)-1-[N-(2-methylpropyl)(4-aminobenzene)sulfonamido]-3-({[(3S)-oxolan-3-yloxy]carbonyl}amino)-4-phenylbutan-2-yl]oxy}phosphonic acid
Clinical data
Trade names	Lexiva
AHFS/Drugs.com	monograph
MedlinePlus	a604012
Pregnancy cat.	C (United States)
Legal status	℞-only (U.S.), POM (UK)
Routes	Oral
Pharmacokinetic data
Bioavailability	Unknown
Protein binding	90%
Metabolism	Hydrolysed to amprenavir and phosphate in GI tract epithelium
Half-life	7.7 hours
Excretion	Fecal (as metabolites of amprenavir)
Identifiers
CAS number	226700-81-8 N
ATC code	J05AE07
PubChem	CID 131536
DrugBank	DB01319
ChemSpider	116245 Y
UNII	WOU1621EEG Y
ChEMBL	CHEMBL1664 Y
NIAID ChemDB	082186
Chemical data
Formula	C25H36N3O9PS
Mol. mass	585.608 g/mol 623.700 g/mol (calcium salt)
SMILES	eMolecules & PubChem
InChI InChI=1S/C25H36N3O9PS/c1-18(2)15-28(39(33,34)22-10-8-20(26)9-11-22)16-24(37-38(30,31)32)23(14-19-6-4-3-5-7-19)27-25(29)36-21-12-13-35-17-21/h3-11,18,21,23-24H,12-17,26H2,1-2H3,(H,27,29)(H2,30,31,32)/t21-,23-,24+/m0/s1 Y Key:MLBVMOWEQCZNCC-OEMFJLHTSA-N Y
N (what is this?)  (verify)

Fosamprenavir (marketed by ViiV Healthcare as fosamprenavir calcium), under the trade names Lexiva (U.S.) and Telzir (Europe) is a pro-drug of the protease inhibitor and antiretroviral drug amprenavir. The FDA approved it October 20, 2003, while the EMEA approved it on July 12, 2004. The human body metabolizes fosamprenavir in order to form amprenavir, which is the active ingredient. That metabolization increases the duration that amprenavir is available, making fosamprenavir a slow-release version of amprenavir and thus reducing the number of pills required versus standard amprenavir.

A head-to-head study with lopinavir showed the two drugs to have comparable potency, but patients on fosamprenavir tended to have a higher serum cholesterol. Fosamprenavir's main advantage over lopinavir is that it is cheaper. Although fosamprenavir does not itself require refrigeration, it is usually given with ritonavir which does.