#最小單位貼紙

抗病毒藥品 CMV retinitis; Prophylaxis of CMV disease

Valganciclovir is the valine ester prodrug that is hydrolyzed to ganciclovir after oral administration. It interferes with viral DNA synthesis and limits replication of all herpes viruses.

Absorption:
1. Well absorbed; high-fat meal increases AUC by 30%
2. Bioavailability (With food): 60%
3. Time to peak: (Ganciclovir) 1.7 to 3 hours
Distribution:
1. Vdss: (Ganciclovir) 0.7 L/kg; widely to all tissue including CSF and ocular tissue
2. Protein binding: (Ganciclovir) 1% to 2%
Metabolism:
1. Converted to ganciclovir by intestinal mucosal cells and hepatocytes.
2. Half-life elimination (Ganciclovir, Mean range):
(1) 1 to <4 months: 3.5 hours; 4 months to 2 years: 2.8 to 4.5 hours; 2 to 12 years: 2.8 to 4.8 hours; 12 to 16 years: 4.4 to 6 hours
(2) Adults: 4.08 hours; prolonged with renal impairment
Excretion:
Urine (80% to 90%; primarily as ganciclovir)

1. Hypersensitivity to valganciclovir or ganciclovir
2. Absolute neutrophil count ＜500/mm3, platelet count ＜25,000/mm3 or Hgb＜8 gm/dL
3. Patients on hemodialysis

C; Fetal risk cannot be ruled out

Avoided

Neutropenia (most common), thrombocytopenia, anemia, headache, insomnia, abdominal pain, diarrhea, nausea, vomiting

Cytomegalovirus (CMV) retinitis, treatment (AIDS-related):
1. Induction: 900 mg twice daily for 14 to 21 days followed by maintenance therapy
2. Maintenance: 900 mg once daily; may consider discontinuation in patients that have received 3 to 6 months of treatment, have inactive lesions, and CD4 count >100 cells/mm3 for 3 to 6 months in response to antiretroviral therapy
CMV, prophylaxis (solid organ transplant recipients):
900 mg once daily; duration of prophylaxis is dependent on type of transplant, as well as donor and recipient CMV serostatus

Treatment dose:
1. CrCl ≥60 mL/min: usual dose (900 mg twice daily)
2. CrCl 40-59 mL/min: 450 mg twice daily
3. CrCl 25-39 mL/min: 450 mg once daily
4. CrCl 10-24 mL/min: 450 mg every 2 days
5. CrCl <10 mL/min: not recommended
Maintenance dose:
1. CrCl ≥60 mL/min: usual dose (900 mg once daily)
2. CrCl 40-59 mL/min: 450 mg once daily
3. CrCl 25-39 mL/min: 450 mg every 2 days
4. CrCl 10-24 mL/min: 450 mg twice weekly
5. CrCl <10 mL/min, hemodialysis: not recommended