Ganciclovir dosage

Other CMV infections IV Initially, 10mg/kg/dayindivideddosesql2hfor 14-21 days, then 5 mg/kg/day as a single daily dose. Maintenance 1000 mg 3 times a day or 500 mg q3h (6 times a day). Intravitreal implant 1 implant q6-9mo plus oral ganciclovir. Dosage in renal impairment Dosage and frequency are modified based on creatinine clearance. 

Teratogenicity, embryotoxicity, irreversible reproductive toxicity, and myelotoxicity have been observed in animals at ganciclovir dosages comparable with those used in human beings. Ganciclovir is classified in pregnancy as category C. 

Patient monitoring Because of the frequency of granulocytopenia, anemia, and thrombocytopenia, it is recommended that CBCs and platelet counts be performed frequently, especially in patients in whom ganciclovir or other nucleoside analogs have previously resulted in cytopenia, or in whom neutrophil counts are less than 1000/mcL at the beginning of treatment. Patients should have serum creatinine or Ccr values followed carefully to allow for dosage adjustment in renally impaired patients. 

Renal function impairment Use ganciclovir with caution. Half-life and plasma/serum concentrations of ganciclovir will be increased because of reduced renal clearance (see Administration and Dosage). 

If renal function is impaired, dosage adjustments are required for ganciclovir IV and should be considered for oral ganciclovir. Base such adjustments on measured or estimated Ccr values. 

Myelosuppression is the most common serious adverse effect of ganciclovir treatment therefore, patients blood counts should be closely monitored. Neutropenia and anemia have been reported in 25 to 30% of patients, and thrombocytopenia has been seen in 5 to 10%. Elevated serum creatinine may occur following ganciclovir treatment, and dosage adjustment is required for patients with renal impairment. In animal studies, ganciclovir causes decreased sperm production, teratogenesis, and tumor formation. 

Zidovudine should be used cautiously with any other agent that causes bone marrow suppression, such as interferon-a, trimethoprim-sulfamethoxazole, dap-sone, foscarnet, flucytosine, ganciclovir, and valganci-clovir. Probenecid and interferon-p inhibit the elimination of zidovudine therefore, a dosage reduction of zidovudine is necessary when the drugs are administered concurrently. Ribavirin inhibits the phosphorylation reactions that activate zidovudine, and zidovudine similarly inhibits the activation of stavudine thus, the coadministration of zidovudine with ribavirin or stavudine is contraindicated. 

Dosage Crcl (ml/min) induction dose maintenance dose > 60 900 mg twice daily 900 mg once daily 40-59 450 mg twice daily 450 mg once daily 25-39 450 mg once daily 450 mg every 2 days 10-24 450 mg every 2 days 450 mg twice weekly Hemodialysis reduces plasma concentration of ganciclovir by 50% following valganciclovir administration, patients receiving hemodialysis should not use valganciclovir because the daily dose is less than 450 mg... 

Brown, F. Banken, L. Saywell, K. Arum, I. Pharmacokinetics of valganciclovir and ganciclovir following multiple oral dosages of valganciclovir in HIV- and CMV-seropositive volunteers, Clin.Pharmacokinet.y 1999,37, 167-176. 

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