Pharmacokinetics of valaciclovir.
While active against Herpesviridae, oral aciclovir is limited by low and inconsistent bioavailability. Modification of aciclovir by valine esterification, producing valaciclovir, results in significant increases in systemic aciclovir plasma levels. The exact mechanism of increased absorption with valaciclovir is not fully determined but probably involves intestinal dipeptide transporters, followed by rapid ester hydrolysis in the small intestine and liver. The enhanced pharmacokinetics of valaciclovir have translated into improvements in clinical efficacy and patient convenience.
MacDougall
Conan
C
Department of Clinical Pharmacy, School of Pharmacy, University of California, San Francisco, CA, USA.
Guglielmo
B Joseph
BJ
D000212:Acyclovir / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D000818:Animals; D000998:Antiviral Agents / Q000493:pharmacokinetics*; D001711:Biotransformation; D002352:Carrier Proteins / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D000074011:Peptide Transporter 1; D027981:Symporters; D000077483:Valacyclovir; D014633:Valine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*
D000998:Antiviral Agents; D002352:Carrier Proteins; D000074011:Peptide Transporter 1; C082186:SLC15A1 protein, human; D027981:Symporters; D014633:Valine; D000077483:Valacyclovir; D000212:Acyclovir