Valganciclovir Dosage for CMV Infection
For adults with CMV retinitis, the recommended valganciclovir dosage is 900 mg orally twice daily for 21 days for induction therapy, followed by 900 mg once daily for maintenance therapy. 1, 2
Adult Dosing Recommendations
CMV Retinitis
- Induction therapy: Valganciclovir 900 mg orally twice daily for 21 days 1, 2, 3
- Maintenance therapy: Valganciclovir 900 mg orally once daily 1, 2, 3
- Valganciclovir is well absorbed from the gastrointestinal tract and rapidly metabolized to ganciclovir in the intestine and liver 1
- The 900 mg dose of valganciclovir provides systemic exposure similar to intravenous ganciclovir 5 mg/kg 4, 3
CMV Colitis
- Initial treatment: Intravenous ganciclovir 5 mg/kg twice daily for 3-5 days 1
- Followed by: Oral valganciclovir 900 mg twice daily for 2-3 weeks 1
- Consider consultation with an infectious disease specialist early in treatment 1
Pediatric Dosing Considerations
- Limited data exists on appropriate valganciclovir dosing for children with CMV infection 1
- For children old enough to receive the adult dosage, valganciclovir is preferred over oral ganciclovir 1
- In younger children, dosing must be adjusted based on body weight and renal function 1, 2
- Valganciclovir is not indicated for prophylaxis in neonates less than 1 month of age due to uncertainty in pharmacokinetic model predictions 2
Dosing in Special Populations
Renal Impairment
- Dose reduction is required for patients with impaired renal function 2
- Valganciclovir should not be used in adult hemodialysis patients (CrCl less than 10 mL/min) 2
- Renal function should be monitored regularly during treatment 1, 2
Elderly Patients
- Dose selection should be cautious, usually starting at the lower end of the dosing range 2
- Elderly patients are more likely to have decreased renal function requiring dose adjustment 2
Monitoring During Treatment
- Regular monitoring of complete blood count is essential due to the risk of myelosuppression 1
- Monitor renal function regularly as renal toxicity can occur 1, 2
- For CMV retinitis, regular ophthalmologic examinations are required 1
Common Adverse Effects
- Major adverse effect is myelosuppression (neutropenia, anemia, thrombocytopenia) 1, 3
- Dose reduction or interruption might be necessary in up to 40% of patients due to hematologic toxicity 1
- Other adverse effects include gastrointestinal symptoms, CNS effects, and elevated liver enzymes 1, 3
Clinical Pearls
- Valganciclovir is a prodrug of ganciclovir with significantly better oral bioavailability 5, 4
- For CMV retinitis in HIV-infected patients, valganciclovir allows for oral treatment during both induction and maintenance phases, avoiding the need for intravenous therapy 5, 3
- In transplant patients, lower doses (450 mg daily) may provide adequate prophylaxis against CMV infection 6, 7
- Combination therapy with ganciclovir and foscarnet may be considered for sight-threatening disease or in cases of treatment failure 1