DOSAGE AND ADMINISTRATION
Strict adherence to dosage recommendations is essential to avoid overdose. Valcyte tablets cannot be substituted for ganciclovir capsules on a one-to-one basis.
Valcyte tablets are administered orally, and should be taken with food (see CLINICAL PHARMACOLOGY: Absorption). After oral administration, valganciclovir is rapidly and extensively converted into ganciclovir. The bioavailability of ganciclovir from Valcyte tablets is significantly higher than from ganciclovir capsules. Therefore the dosage and administration of Valcyte tablets as described below should be closely followed (see PRECAUTIONS: General and OVERDOSAGE).
For the Treatment of CMV Retinitis in Patients With Normal Renal Function
Induction
For patients with active CMV retinitis, the recommended dosage is 900 mg (two 450 mg tablets) twice a day for 21 days with food.
Maintenance
Following induction treatment, or in patients with inactive CMV retinitis, the recommended dosage is 900 mg (two 450 mg tablets) once daily with food.
For the Prevention of CMV Disease in Heart, Kidney, and Kidney-Pancreas Transplantation
For patients who have received a kidney, heart, or kidney-pancreas transplant, the recommended dose is 900 mg (two 450 mg tablets) once daily with food starting within 10 days of transplantation until 100 days posttransplantation.
Renal Impairment
Serum creatinine or creatinine clearance levels should be monitored carefully. Dosage adjustment is required according to creatinine clearance as shown in Table 13 (see PRECAUTIONS: General and CLINICAL PHARMACOLOGY: Special Populations: Renal Impairment). Increased monitoring for cytopenias may be warranted in patients with renal impairment (see PRECAUTIONS: Laboratory Testing).
Table 13 Dose Modifications for Patients With Impaired Renal Function CrClAn estimated creatinine clearance can be related to serum creatinine by the following formulas:
For males = (140 − age [years]) × (body weight [kg])
(72) × (serum creatinine [mg/dL])
For females = 0.85 × male value (mL/min) | Induction Dose | Maintenance Prevention 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 Patients
Valcyte should not be prescribed to patients receiving hemodialysis (see CLINICAL PHARMACOLOGY: Special Populations: Hemodialysis and PRECAUTIONS: General).
For patients on hemodialysis (CrCl <10 mL/min) a dose recommendation cannot be given (see CLINICAL PHARMACOLOGY: Special Populations: Hemodialysis).
Handling and Disposal
Caution should be exercised in the handling of Valcyte tablets. Tablets should not be broken or crushed. Since valganciclovir is considered a potential teratogen and carcinogen in humans, caution should be observed in handling broken tablets (see WARNINGS: Teratogenesis, Carcinogenesis and Mutagenesis). Avoid direct contact of broken or crushed tablets with skin or mucous membranes. If such contact occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with plain water.
Because ganciclovir shares some of the properties of antitumor agents (ie, carcinogenicity and mutagenicity), consideration should be given to handling and disposal according to guidelines issued for antineoplastic drugs. Several guidelines on this subject have been published (see REFERENCES).
There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate.
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