Valacyclovir Hydrochloride (Page 2 of 13)

Chickenpox

The recommended dosage of valacyclovir for treatment of chickenpox in immunocompetent pediatric patients aged 2 to less than 18 years is 20 mg/kg administered 3 times daily for 5 days. The total dose should not exceed 1 gram 3 times daily. Therapy should be initiated at the earliest sign or symptom [see Use in Specific Populations (8.4), Clinical Pharmacology (12.3), Clinical Studies (14.4)].

2.3 Extemporaneous Preparation of Oral Suspension

Ingredients and Preparation per USP-NF

Valacyclovir tablets 500 mg, cherry flavor, and Suspension Structured Vehicle USP-NF (SSV). Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) should be prepared in lots of 100 mL.

Instructions for Preparing Suspension at Time of Dispensing

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Prepare SSV according to the USP-NF.

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Using a pestle and mortar, grind the required number of valacyclovir 500-mg tablets until a fine powder is produced (5 valacyclovir tablets for 25-mg/mL suspension; 10 valacyclovir tablets for 50-mg/mL suspension).

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Gradually add approximately 5-mL aliquots of SSV to the mortar and triturate the powder until a paste has been produced. Ensure that the powder has been adequately wetted.

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Continue to add approximately 5-mL aliquots of SSV to the mortar, mixing thoroughly between additions, until a concentrated suspension is produced, to a minimum total quantity of 20 mL SSV and a maximum total quantity of 40 mL SSV for both the 25-mg/mL and 50- mg/mL suspensions.

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Transfer the mixture to a suitable 100-mL measuring flask.

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Transfer the cherry flavor* to the mortar and dissolve in approximately 5 mL of SSV. Once dissolved, add to the measuring flask.

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Rinse the mortar at least 3 times with approximately 5-mL aliquots of SSV, transferring the rinsing to the measuring flask between additions.

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Make the suspension to volume (100 mL) with SSV and shake thoroughly to mix.

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Transfer the suspension to an amber glass medicine bottle with a child-resistant closure.

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The prepared suspension should be labeled with the following information “Shake well before using. Store suspension between 2° to 8°C (36° to 46°F) in a refrigerator. Discard after 28 days.”

*The amount of cherry flavor added is as instructed by the suppliers of the cherry flavor.

2.4 Patients with Renal Impairment

Dosage recommendations for adult patients with reduced renal function are provided in Table 1 [see Use in Specific Populations (8.5, 8.6), Clinical Pharmacology (12.3)]. Data are not available for the use of valacyclovir in pediatric patients with a creatinine clearance less than 50 mL/min/1.73 m².

Table 1. Valacyclovir Tablets Dosage Recommendations for Adults with Renal Impairment

Indications	Normal Dosage Regimen (Creatinine Clearance ≥ 50 mL/min)	Creatinine Clearance (mL/min)
		30-49	10-29	< 10
Cold sores (Herpes Labialis) Do not exceed 1 day of treatment.	Two 2-gram doses taken 12 hours apart	Two 1-gram doses taken 12 hours apart	Two 500-mg doses taken 12 hours apart	500-mg single dose
Genital herpes: Initial episode	1 gram every 12 hours	no reduction	1 gram every 24 hours	500 mg every 24 hours
Genital herpes: Recurrent episode	500 mg every 12 hours	no reduction	500 mg every 24 hours	500 mg every 24 hours
Genital herpes: Suppressive therapy
Immunocompetent patients	1 gram every 24 hours	no reduction	500 mg every 24 hours	500 mg every 24 hours
Alternate dose for immunocompetent patients with less than or equal to 9 recurrences/year	500 mg every 24 hours	no reduction	500 mg every 48 hours	500 mg every 48 hours
HIV-1–infected patients	500 mg every 12 hours	no reduction	500 mg every 24 hours	500 mg every 24 hours
Herpes zoster	1 gram every 8 hours	1 gram every 12 hours	1 gram every 24 hours	500 mg every 24 hours

Hemodialysis

Patients requiring hemodialysis should receive the recommended dose of valacyclovir tablets after hemodialysis. During hemodialysis, the half-life of acyclovir after administration of valacyclovir tablets is approximately 4 hours. About one-third of acyclovir in the body is removed by dialysis during a 4-hour hemodialysis session.