There are 3: valacyclovir, acyclovir, and topical penciclovir. valacyclovir, 2 g twice in 1 day taken during the prodromal stage of herpes labialis, reduces the episode duration and time to healing. Acyclovir, 400 mg, taken 5 times a day for 5 days, decreases the pain duration and healing time to loss of crust (strength of recommendation [sor]: a, based on randomized controlled trials [rCTs]). ...

A meta-analysis of 12 randomized trials (1574 patients) examined herpesvirus and related outcomes following organ transplantation over a range of acyclovir exposures (including valacyclovir). Overall, cytomegalovirus (CMV) infection (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.34-0.57; P<.001), CMV disease (OR, 0.41; 95% CI, 0.31-0.54; P<.001), death (OR, 0.60; 95% CI, 0.40-0.90; P=....

OBJECTIVE Genital herpes (GH) recurrences and viral shedding are more frequent in the first year after initial HSV-2 infection. The objective of this study was to provide the first evaluation of valacyclovir 1 g once daily compared to placebo in reducing viral shedding in subjects newly diagnosed with GH. METHODS 70 subjects were randomized to receive valacyclovir 1 g daily or placebo in a cr...

The primary objective of this study was to determine the in vivo absorption properties of valacyclovir, including the potential for saturable proton-coupled oligopeptide transporter 1 (PepT1)-mediated intestinal uptake, after escalating oral doses of prodrug within the clinical dose range. A secondary aim was to characterize the role of PepT1 on the tissue distribution of its active metabolite,...

The purpose of this study was twofold. The first aim was to evaluate the oral bioavailability and pharmacokinetics (PKs) of acyclovir in horses after intravenous (i.v.) administration and after oral administration of acyclovir and its prodrug, valacyclovir. Second, we aimed to combine these PK data with pharmacodynamic (PD) information, i.e., 50% effective concentrations (EC(50) values) from in...

BACKGROUND Recurrent genital herpes is a major problem for patients worldwide. Early episodic treatment with short-course therapy is effective, often stopping progression of outbreaks. This study is the first head-to-head comparison of single-day famciclovir (1000 mg administered twice daily) versus 3-day valacyclovir (500 mg administered twice daily) for episodic therapy in immunocompetent pat...

BACKGROUND Studies in HIV-1-infected infants and HIV-1-exposed, uninfected infants link early cytomegalovirus (CMV) acquisition with growth delay and cognitive impairment. We investigated maternal valacyclovir to delay infant acquisition of CMV. METHODS Pregnant women with HIV-1, HSV-2 and CD4 count >250 cells/µl were randomized at 34 weeks gestation to 500 mg twice-daily valacyclovir or plac...

Despite peptide transporter 1 (PEPT1) being responsible for the bioavailability for a variety of drugs, there has been little study of its potential involvement in drug-drug interactions. Pomaglumetad methionil, a metabotropic glutamate 2/3 receptor agonist prodrug, utilizes PEPT1 to enhance absorption and bioavailability. In vitro studies were conducted to guide the decision to conduct a clini...

L-Valacyclovir, a prodrug of acyclovir, is a substrate for the peptide transporter (PepT1) in the intestinal mucosa, which accounts for its higher than expected oral bioavailability. The substrate activity of L-valacyclovir for PepT1 is surprising, particularly when one considers that the molecule has the structural features of a nucleoside rather than a peptide. In an attempt to better underst...