VALGANCICLOVIR

'Valganciclovir hydrochloride' ('Valcyte', manufactured by Roche) 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.

Contents

Administration

Pharmacokinetics

Side effects

Alternative uses

References

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

# Oral bioavailability is approximately 60%. Fatty foods significantly increase the bioavailability and the peak level in the serum.
# It takes about 2 hours to reach maximum concentrations in the serum.
# 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

Alternative uses

It has been proposed that valganciclovir could be used in the treatment of chronic fatigue syndrome, following some reported success in 9 out of 12 patients at Stanford University in California, although further research is required [1]. A study is planned at Stanford for early 2007. [2]

References

# Kogelnik AM et al Use of valganciclovir in patients with elevated antibody titers against Human Herpesvirus-6 (HHV-6) and Epstein-Barr Virus (EBV) who were experiencing central nervous system dysfunction including long-standing fatigue. J Clin Virol. 2006;37(S1):S33-S38.
# 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.
# Pescovitz MD et al Valganciclovir results in improved oral absorption of ganciclovir in liver transplant recipients. Antimicrob Agents Chemother. 2000;44(10):2811-5.
# Reusser P. Antiviral therapy: current options and challenges. Schweiz Med Wochenschr. 2000;130(4):101-12.
# 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.