Single-dose pharmacokinetics of valganciclovir in HIV- and CMV-seropositive subjects.
As a result of the low oral bioavailability of ganciclovir, a prodrug was developed to improve the bioavailability of ganciclovir. This study was designed to investigate the fasting, single-dose pharmacokinetics as well as the absolute and relative bioavailability of a valine ester prodrug of ganciclovir, valganciclovir, as compared to oral and intravenous ganciclovir in asymptomatic HIV+ and CMV+ subjects. In this open-label, randomized, three-period crossover study, 18 subjects received, in random order, single oral doses of valganciclovir 360 mg and ganciclovir 1000 mg and an intravenous infusion of ganciclovir 5 mg/kg over 1 hour. Valganciclovir was rapidly and extensively hydrolyzed to ganciclovir, resulting in significantly greater bioavailability compared to 1000 mg oral ganciclovir (60.9% vs. 5.6%, respectively). Higher peak serum concentrations were reached earlier following valganciclovir (ganciclovir [2.98 +/- 0.77 micrograms/mL at 1.0 +/- 0.3 h]) than following oral ganciclovir (0.47 +/- 0.17 microgram/mL and 2.2 +/- 1.0 h). Mean total ganciclovir AUCs following oral ganciclovir (1000 mg) and 360 mg valganciclovir (3.8 +/- 1.2 and 10.8 +/- 1.9 micrograms-h/mL) were less than that following a standard 5 mg/kg intravenous infusion of ganciclovir (25.1 +/- 3.8 micrograms-h/mL). In summary, valganciclovir is a prodrug with a favorable safety profile with enhanced bioavailability and significantly higher serum concentrations of ganciclovir than following oral administration of ganciclovir itself.
Jung
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Roche Global Development, Palo Alto, California, USA.
Dorr
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D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics; D000998:Antiviral Agents / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D018592:Cross-Over Studies; D003586:Cytomegalovirus Infections / Q000097:blood*; D003967:Diarrhea / Q000139:chemically induced; D004244:Dizziness / Q000139:chemically induced; D004417:Dyspnea / Q000139:chemically induced; D005076:Exanthema / Q000139:chemically induced; D005260:Female; D005334:Fever / Q000139:chemically induced; D015774:Ganciclovir / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood* / Q000493:pharmacokinetics; D006679:HIV Seropositivity; D006261:Headache / Q000139:chemically induced; D006801:Humans; D006973:Hypertension / Q000139:chemically induced; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D010146:Pain / Q000139:chemically induced; D011355:Prodrugs / Q000009:adverse effects / Q000493:pharmacokinetics*; D013575:Syncope / Q000139:chemically induced; D000077562:Valganciclovir
D019380:Anti-HIV Agents; D000998:Antiviral Agents; D011355:Prodrugs; D000077562:Valganciclovir; D015774:Ganciclovir