Comparative Pharmacology
Head-to-head clinical analysis: CYTOVENE versus VALCYTE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYTOVENE versus VALCYTE.
CYTOVENE vs VALCYTE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Ganciclovir is a synthetic guanosine analog that inhibits viral DNA synthesis by competitively inhibiting viral DNA polymerase and by incorporation into viral DNA, causing chain termination. It is phosphorylated intracellularly to ganciclovir triphosphate, which is active against cytomegalovirus (CMV).
Valganciclovir is an L-valyl ester (prodrug) of ganciclovir. After oral administration, it is rapidly hydrolyzed to ganciclovir. Ganciclovir is phosphorylated to ganciclovir triphosphate, which inhibits viral DNA synthesis by competitive inhibition of viral DNA polymerase and incorporation into viral DNA, causing chain termination.
Induction: 5 mg/kg IV every 12 hours for 14-21 days; maintenance: 5 mg/kg IV once daily for 7 days per week or 6 mg/kg IV once daily for 5 days per week
For cytomegalovirus (CMV) retinitis in immunocompromised patients: 900 mg orally twice daily for 21 days, then 900 mg once daily as maintenance. For prevention of CMV in transplant recipients: 900 mg orally once daily starting within 10 days of transplant, continuing up to 100 days post-transplant.
None Documented
None Documented
Terminal elimination half-life: 3-4 hours in normal renal function; prolonged to 28-40 hours in severe renal impairment (CrCl <10 mL/min)
Terminal elimination half-life: 3-5 hours (valganciclovir) and 3.5-4.5 hours (ganciclovir, after conversion). In patients with renal impairment, half-life is prolonged: up to 10-30 hours depending on creatinine clearance. Hemodialysis reduces half-life to approximately 4-5 hours.
Primarily renal excretion as unchanged drug (>90%); 1-2% biliary/fecal
Renal excretion (primarily glomerular filtration and tubular secretion). Approximately 82-90% of the administered dose is recovered unchanged in urine. Fecal excretion is minimal (<5%). Biliary excretion is negligible.
Category C
Category C
Antiviral Agent
Antiviral Agent