Valcyte Dosage/Direction for Use

Caution: Strict adherence to dosage recommendations is essential to avoid overdose.
Standard Dosage: Valcyte is administered orally, and should be taken with food (see Pharmacology: Pharmacokinetics: Absorption and Pharmacokinetics in Special Populations under Actions).
Valcyte is rapidly and extensively converted into the active ingredient ganciclovir. The bioavailability of ganciclovir from Valcyte is up to 10-fold higher than from oral ganciclovir.
The dosage and administration of Valcyte tablets or powder for oral solution as described as follows should be closely followed (see Precautions and Overdosage).
The ganciclovir systemic exposure following administration of 900 mg Valcyte powder for oral solution is equivalent to a 900 mg Valcyte dose administered as two 450 mg tablets.
An oral dosing dispenser with 25 mg graduations up to 500 mg is provided with the powder for oral solution. It is recommended that this dispenser is used to measure and administer the dose.
Treatment of cytomegalovirus (CMV) retinitis: Adult patients: Induction treatment of CMV retinitis: For patients with active CMV retinitis, the recommended dose is 900 mg twice a day for 21 days. Prolonged induction treatment may increase the risk of bone marrow toxicity (see Precautions).
Maintenance treatment of CMV retinitis: Following induction treatment, or in adult patients with inactive CMV retinitis, the recommended dose is 900 mg once daily. Patients whose retinitis worsens may repeat induction treatment (see Induction treatment of CMV retinitis as previously mentioned).
The duration of maintenance treatment should be determined on an individual basis.
Pediatric patients: The safety and efficacy of Valcyte in the treatment of CMV retinitis have not been established in adequate and well-controlled clinical studies in pediatric patients.
Prevention of CMV disease in transplantation: Adult patients: For kidney transplant patients, the recommended dose is 900 mg once daily starting within 10 days post-transplantation and continuing until 200 days post-transplantation.
For patients who have received a solid organ transplant other than kidney, the recommended dose is 900 mg once daily starting within 10 days post-transplantation and continuing until 100 days post-transplantation.
Pediatric patients: In pediatric solid organ transplant patients from birth, who are at risk of developing CMV disease, the recommended once daily dose of Valcyte is based on body surface area (BSA) and creatinine clearance (Clcr) derived from Schwartz formula (ClcrS), and is calculated using the equation as follows:
Pediatric dose (mg) = 7 x BSA x ClcrS (see Mosteller BSA formula and Schwartz Creatinine Clearance formula as follows). If the calculated Schwartz creatinine clearance exceeds 150 mL/min/1.73m², then a maximum value of 150 mL/min/1.73m² should be used in the equation. (See Equation 1.)

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Where k = 0.45* for patients aged <2 years, 0.55 for boys aged 2 to <13 years and girls aged 2 to 16 years, and 0.7 for boys aged 13 to 16 years. Refer to adult dosing for patients older than 16 years of age.
The k values provided are based on the Jaffe method of measuring serum creatinine, and may require correction when enzymatic methods are used.
* A lowering of k value may also be necessary for appropriate sub-populations.
For pediatric kidney transplant patients, the recommended once daily mg dose (7 x BSA x ClcrS) should start within 10 days post-transplantation and continue until 200 days post-transplantation.
For pediatric patients who have received a solid organ transplant other than kidney, the recommended once-daily mg dose (7 x BSA x ClcrS) should start within 10 days post-transplantation and continue until 100 days post-transplantation.
All calculated doses should be rounded to the nearest 25 mg increment for the actual deliverable dose. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. The oral solution is the preferred formulation since it provides the ability to administer a dose calculated according to the formula as previously mentioned; however, Valcyte tablets may be used if the calculated doses are within 10% of available tablet doses, and the patient is able to swallow tablets. For example, if the calculated dose is between 405 mg and 495 mg, one 450 mg tablet may be taken.
It is recommended to monitor serum creatinine levels regularly and consider changes in height and body weight and adapt the dose as appropriate during prophylaxis period.
Special Dosage Instructions: Pediatric patients: Dosing of pediatric SOT patients is individualized based on a patient's renal function and size (see Dosage and Administration as previously mentioned).
Geriatric use: Safety and efficacy have not been established in this patient population. No studies have been conducted in adults older than 65 years of age. Since renal clearance decreases with age, Valcyte should be administered to elderly patients with special consideration of their renal status (see Table 4 and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations: Geriatric Population under Actions).
Adult patients with renal impairment: Serum creatinine or estimated creatinine clearance levels should be monitored carefully. Dosage adjustment is required for adult patients based on creatinine clearance as shown in Table 4 as follows (see Precautions and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions). (See Table 4.)

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Estimated creatinine clearance is calculated from serum creatinine by the following formulae: See Equation 2.

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Hepatic impairment: The safety and efficacy of Valcyte have not been established in patients with hepatic impairment. (see Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations: Hepatic Impairment under Actions).