Valacyclovir

In adults: treatment of cold sores (herpes labialis), genital herpes (initial episode, recurrent episodes, and chronic suppressive therapy, including reduction of transmission), and herpes zoster (shingles). In pediatric patients: cold sores in those 12 years and older, and chickenpox (varicella) in immunocompetent children 2 to less than 18 years of age.

2 DOSAGE AND ADMINISTRATION Valacyclovir tablets may be given without regard to meals. Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) may be prepared extemporaneously from the 500-mg valacyclovir tablets for use in pediatric patients for whom a solid dosage form is not appropriate [see Dosage and Administration (2.3) ]. Adult Dosage ( 2.1 ) Cold Sores 2 grams every 12 hours for 1 day Genital Herpes Initial episode 1 gram twice daily for 10 days Recurrent episodes 500 mg twice daily for 3 days Suppressive therapy Immunocompetent patients 1 gram once daily Alternate dose in patients with less than or equal to 9 recurrences/year 500 mg once daily HIV-1-infected patients 500 mg twice daily Reduction of transmission 500 mg once daily Herpes Zoster 1 gram 3 times daily for 7 days Pediatric Dosage ( 2.2 ) Cold Sores (aged greater than or equal to 12 years) 2 grams every 12 hours for 1 day Chickenpox (aged 2 to less than 18 years) 20 mg/kg 3 times daily for 5 days; not to exceed 1 gram 3 times daily Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) can be prepared from the Valacyclovir Tablets, USP 500 mg. ( 2.3 ) 2.1 Adult Dosing Recommendations Cold Sores (Herpes Labialis) The recommended dosage of valacyclovir tablets for treatment of cold sores is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning). Genital Herpes Initial Episode: The recommended dosage of valacyclovir tablets for treatment of initial genital herpes is 1 gram twice daily for 10 days. Therapy was most effective when administered within 48 hours of the onset of signs and symptoms. Recurrent Episodes: The recommended dosage of valacyclovir tablets for treatment of recurrent genital herpes is 500 mg twice daily for 3 days. Initiate treatment at the first sign or symptom of an episode. Suppressive Therapy: The recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 1 gram once daily in patients with normal immune function. In patients with a history of 9 or fewer recurrences per year, an alternative dose is 500 mg once daily. In HIV-1-infected patients with a CD4+ cell count greater than or equal to 100 cells/mm 3 , the recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 500 mg twice daily. Reduction of Transmission: The recommended dosage of valacyclovir tablets for reduction of transmission of genital herpes in patients with a history of 9 or fewer recurrences per year is 500 mg once daily for the source partner. Suppressive Therapy: The recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 1 gram once daily in patients with normal immune function. In patients with a history of 9 or fewer recurrences per year, an alternative dose is 500 mg once daily. In HIV-1-infected patients with a CD4+ cell count greater than or equal to 100 cells/mm 3 , the recommended dosage of valacyclovir tablets for chronic suppressive therapy of recurrent genital herpes is 500 mg twice daily. Reduction of Transmission: The recommended dosage of valacyclovir tablets for reduction of transmission of genital herpes in patients with a history of 9 or fewer recurrences per year is 500 mg once daily for the source partner. Herpes Zoster The recommended dosage of valacyclovir tablets for treatment of herpes zoster is 1 gram 3 times daily for 7 days. Therapy should be initiated at the earliest sign or symptom of herpes zoster and is most effective when started within 48 hours of the onset of rash. 2.2 Pediatric Dosing Recommendations Cold Sores (Herpes Labialis) The recommended dosage of valacyclovir tablets for the treatment of cold sores in pediatric patients aged greater than or equal to 12 years is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning). Chickenpox The recommended dosage of valacyclovir tablets 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 Prepare SSV according to the USP-NF. Using a pestle and mortar, grind the required number of valacyclovir tablets 500-mg until a fine powder is produced (5 valacyclovir tablets for 25-mg/mL suspension; 10 valacyclovir tablets for 50-mg/mL suspension). 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. 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. Transfer the mixture to a suitable 100-mL measuring flask. Transfer the cherry flavor The amount of cherry flavor added is as instructed by the suppliers of the cherry flavor. to the mortar and dissolve in approximately 5 mL of SSV. Once dissolved, add to the measuring flask. Rinse the mortar at least 3 times with approximately 5-mL aliquots of SSV, transferring the rinsing to the measuring flask between additions. Make the suspension to volume (100 mL) with SSV and shake thoroughly to mix. Transfer the suspension to an amber glass medicine bottle with a child-resistant closure. 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." 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 tablets in pediatric patients with a creatinine clearance less than 50 mL/min/1.73 m 2 . 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. Peritoneal Dialysis There is no information specific to administration of valacyclovir tablets in patients receiving peritoneal dialysis. The effect of chronic ambulatory peritoneal dialysis (CAPD) and continuous arteriovenous hemofiltration/dialysis (CAVHD) on acyclovir pharmacokinetics has been studied. The removal of acyclovir after CAPD and CAVHD is less pronounced than with hemodialysis, and the pharmacokinetic parameters closely resemble those observed in patients with end-stage renal disease (ESRD) not receiving hemodialysis. Therefore, supplemental doses of valacyclovir tablets should not be required following CAPD or CAVHD.