Fosamprenavir calcium

Molecular formula C25H36CaN309PS Molecular weight 625.68 CAS Registry No 226700-81-8 

Sample preparation Vortex 100 LL plasma with 200 p-L 1 p-g/mL IS in MeCN, centrifuge. Mix a 100 [xL aliquot of the supernatant with 100 xL 0.1% formic acid and 400 LL MeCNiwater 50 50, inject a 10-20 p.L aliquot. 

Detector MS, PE Sciex API2000 turbo ion spray, electrospray ionization, positive ion mode 

WooUey, J.L. Brouwer, K.R. Serabjit-Singh, C. Polli, J.W. Induction of P-glycoprotein and cytochrome P450 3A by HIV protease inhibitors, Drug Metab.Dispos., 2001, 29, 754-760. 

Sample preparation Mix 100 xL plasma with 500 (tL EtOH MeCN 50 50, centrifuge at 15 800 g at 4° for 5 min. Evaporate the supernatant to dr5tness, reconstitute the residue with 100 (tL initial mobile phase, inject a 10 (tL aliquot. 

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Similar labeling language also in the labeling of INVIRASE (Roche Laboratories) (saquinavir mesylate) capsules, December 2003 KALETRA (Abbott) (lopinavir/ritonavir) capsules, (lopinavir/ritonavir) oral solution, February 2004 and LEXIVA (GlaxoSmithKline) (fosamprenavir calcium) tablets. May 2004. 

Fosamprenavir calcium has been approved for the treatment of HIV in adults when used in combination with other anti-HIV drugs. It is a prodrug that, on hydrolysis by serum phosphatases, gives rise to amprenavir, which is a peptidomimetic transition-state inhibitor that targets HIV-1 protease and reduces the viral replication and, thus, the infectiousness of HIV-1. It is commonly administered in combination with RT inhibitors to produce excellent efficacy in patients with AIDS. The drug is administered as two 700 mg tablets twice daily or, in combination with ritonavir, can be given as two 700 mg tables once daily or one 700 mg tablet twice daily. As a result, formaprenavir lowers the pill burden in patients with AIDS. 

Lexiva (Fosamprenavir calcium). GlaxoSmithKline. US Prescribing information, June 2007. 

Telzir (Fosamprenavir calcium). Gl oSmitiiKltne UK. UK Summary of product characteristics, Februaty 2007. 

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