Valaciclovir (INN) or valacyclovir (USAN) is an antiviral drug used in the management of herpes simplex and herpes zoster (shingles). It is a prodrug, being converted in vivo to aciclovir. It is marketed by GlaxoSmithKline under the trade name Valtrex.

Pharmacology

---

Mechanism of action

Valaciclovir is a prodrug that is converted by esterases to the active drug aciclovir via hepatic first-pass metabolism. Aciclovir is selectively converted into a monophosphate form by viral thymidine kinase, which is far more effective (3000 times) in phosphorylation than cellular thymidine kinase. Subsequently, the monophosphate form is further phosphorylated into the active triphosphate form, aciclo-GTP, by cellular kinases. Aciclo-GTP is a very potent inhibitor of viral DNA polymerase; it has approximately 100 times higher affinity to viral than cellular polymerase. Its monophosphate form also incorporates into the viral DNA, resulting in chain termination. It has also been shown that the viral enzymes cannot remove aciclo-GMP from the chain, which results in inhibition of further activity of DNA polymerase. Aciclo-GTP is fairly rapidly metabolised within the cell, possibly by cellular phosphatases.

Microbiology

Aciclovir, the active metabolite of valaciclovir, is active against most species in the herpesvirus family. In descending order of activity:O'Brien JJ, Campoli-Richards DM. Acyclovir. An updated review of its antiviral activity, pharmacokinetic properties and therapeutic efficacy. Drugs 1989;37(3):233-309. PMID 2653790

• Herpes simplex virus type I (HSV-1)
• Herpes simplex virus type II (HSV-2)
• Varicella zoster virus (VZV)
• Epstein-Barr virus (EBV)
• Cytomegalovirus (CMV)

More on [ Valaciclovir ]

Valacyclovir - Twitter Search

Speed Healing With Valtrex: In a study of people younger than 50 years old with shingles, Valtrex (valacyclovir) w... http://bit.ly/89z4sc
ow_infectious_d (OrganizedWisdom) Thu, 07 Jan 2010 22:06:26 -0000
Speed Healing With Valtrex: In a study of people younger than 50 years old with shingles, Valtrex (valacyclovir) w... http://bit.ly/89z4sc
what is Valacyclovir Hydrochlorideand about its side effect, complications, dosage, who is it for, p http://bit.ly/4JIGtp
inzend11 (hran minu) Thu, 07 Jan 2010 09:21:17 -0000
what is Valacyclovir Hydrochlorideand about its side effect, complications, dosage, who is it for, p http://bit.ly/4JIGtp
Viagra with out prescription - Men`s Health: Valacyclovir will not prevent viruses include genital herpes (glucose)... http://bit.ly/8FSFVL
lovehstyle (Love, H Style) Mon, 04 Jan 2010 01:01:10 -0000
Viagra with out prescription - Men`s Health: Valacyclovir will not prevent viruses include genital herpes (glucose)... http://bit.ly/8FSFVL

Subscribe to Valacyclovir RSS feed