Valcyte (valganciclovir hydrochloride) is an antiviral prodrug, whose main component is valganciclovir hydrochloride. After oral administration, it is rapidly converted into ganciclovir in the body. As a CMV-specific inhibitor, it effectively inhibits the replication of human cytomegalovirus (CMV) by competitively blocking viral DNA polymerase.
Indications of Valcyte
Core Indications
Treatment of CMV Retinitis: Specifically used for the treatment of active or inactive CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS), including induction phase (21 days) and maintenance phase treatment.
Prophylaxis in Transplant Patients: To be adjusted in accordance with clinical guidelines, it is used for CMV prophylaxis in patients who have undergone solid organ transplantation (off-label use).
Pharmacological Actions
After being absorbed through the intestinal tract, the drug is converted into ganciclovir by esterases in the intestinal wall and liver.
In CMV-infected cells, ganciclovir is phosphorylated into its active form by the viral kinase pUL97, which inhibits viral DNA synthesis and ultimately terminates viral replication.
Specifications and Properties of Valcyte
Dosage Form and Composition
Dosage Form: Film-coated tablets, with an oval convex design, engraved with "VGC" and "450" marks.
Specification: Each tablet contains 450 mg of valganciclovir (equivalent to 496.3 mg of valganciclovir hydrochloride).
Physicochemical Characteristics
Appearance: Pink-coated tablets, coated with Opadry Pink® film coating.
Chemical Properties
Molecular Formula: C₁₄H₂₂N₆O₅·HCl
Molecular Weight: 390.83
Water Solubility: 70 mg/mL (pH 7.0, 25°C)
Stability: Store in a light-resistant container at 25°C (allowable range: 15-30°C).
Usage and Dosage of Valcyte
Standard Dosing Regimen
Induction Therapy: 900 mg (2 tablets) twice daily, taken with meals, for 21 consecutive days.
Maintenance Therapy: 900 mg once daily, used long-term until disease progression or occurrence of intolerable toxicity.
Dosage Adjustment for Renal Impairment
Creatinine Clearance (CrCl) ≥ 60 mL/min: Full dose.
CrCl 40-59 mL/min: 450 mg twice daily during the induction phase, and 450 mg once daily during the maintenance phase.
CrCl 25-39 mL/min: 450 mg once daily or once every other day.
CrCl 10-24 mL/min: 450 mg once every 2 days or twice a week.
Contraindication: Contraindicated in hemodialysis patients (CrCl < 10 mL/min).
Monitoring Indicators
Complete blood count (with focus on neutrophils and platelets) should be tested weekly.
Renal function (serum creatinine or CrCl) should be evaluated regularly.
Contraindicated Combinations
Concurrent use with zidovudine is prohibited (as it may exacerbate myelosuppression).
Concurrent use with nephrotoxic drugs or probenecid should be avoided.
