Valganciclovir hydrochloride (Valcyte®) is an antiviral medication used to treat cytomegalovirus infections. As the L-valyl ester of ganciclovir, it is actually a prodrug for ganciclovir. After oral administration, it is rapidly converted to ganciclovir by intestinal and hepatic esterases.

Administration

Orally, available in 450 mg pink tablets. Dosing is calculated to provide appropriate doses of ganciclovir; 900 mg of valganciclovir orally every 12 hours is equivalent to 5 mg per kilogram of body weight of intravenous ganciclovir, also every 12 hours.

Pharmacokinetics

1. Oral bioavailability is approximately 60%. Fatty foods significantly increase the bioavailability and the peak level in the serum.
2. It takes about 2 hours to reach maximum concentrations in the serum.
3. Valganciclovir is eliminated as ganciclovir in the urine, with a half-life of about 4 hours in people with normal kidney function.

Side effects

• Blood: neutropenia, anemia, low platelets. Myelosuppression is one of the main side effects that may limit prolonged use of valganciclovir.
• Gastrointestinal: diarrhea, nausea, vomiting, abdominal pain.
• Central nervous system: fever, headache, insomnia, paresthesia, and peripheral neuropathy.
• Ocular: retinal detachment

References

1. Paltiel AD et al Preevaluation of clinical trial data: the case of preemptive cytomegalovirus therapy in patients with human immunodeficiency virus. Clin Infect Dis. 2001;32(5):783-93.
2. Pescovitz MD et al Valganciclovir results in improved oral absorption of ganciclovir in liver transplant recipients. Antimicrob Agents Chemother. 2000;44(10):2811-5.
3. Reusser P. Antiviral therapy: current options and challenges. Schweiz Med Wochenschr. 2000;130(4):101-12.
4. Sugawara M, Huang W, Fei YJ, et al. Transport of valganciclovir, a ganciclovir prodrug, via peptide transporters PEPT1 and PEPT2. J Pharm Sci. 2000;89(6):781-9.

antivirals

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