Valtrex Dosage/Direction for Use

Adults: Treatment of Herpes Zoster: 1000 mg to be taken 3 times daily for 7 days.
Treatment of Herpes Simplex Infections: 500 mg to be taken twice daily.
For recurrent episodes, treatment should be for 3 or 5 days. For initial episodes, which can be more severe, treatment may have to be extended from 5-10 days. Dosing should begin as early as possible. For recurrent episodes of Herpes simplex, this should ideally be during the prodromal period or immediately after the 1st signs or symptoms appear. Valtrex can prevent lesion development when taken at the first signs and symptoms of an Herpes simplex virus recurrence.
Alternatively, for Herpes labialis (cold sores), 2 g twice-daily for 1 day is an effective treatment. The 2nd dose should be taken about 12 hrs (no sooner than 6 hrs) after the 1st dose. When using this dosage regimen, treatment should not exceed 1 day, since this has been shown not to provide additional clinical benefit. Therapy should be initiated at the earliest symptom of a cold sore (eg, tingling, itching, or burning).
Prevention (Suppression) of Recurrences of Herpes Simplex Infections: In immunocompetent patients, 500 mg once daily.
Some patients with very frequent recurrences (eg, ≥10/year) may gain additional benefit from the daily dose of 500 mg being taken as a divided dose (250 mg twice daily).
For immunocompromised patients, the dose is 500 mg twice daily.
Reduction of Transmission of Genital Herpes: In immunocompetent heterosexual adults with ≤9 recurrences/year, 500 mg to be taken once daily by the infected partner.
There are no data on the reduction of transmission in other patient populations.
Prophylaxis of CMV Infection and Disease: Adults and Adolescents ≥12 years: 2 g 4 times daily, to be initiated as early as possible post-transplant. This dose should be reduced according to creatinine clearance (see Renal Impairment).
The duration of treatment will usually be 90 days, but may need to be extended in high risk patients.
Children: There are no data available on the use of Valtrex in children.
Elderly: The possibility of renal impairment in the elderly must be considered and the dosage should be adjusted accordingly (see Renal Impairment).
Adequate hydration should be maintained.
Renal Impairment: Caution is advised when administering valaciclovir to patients with impaired renal function. Adequate hydration should be maintained.
Herpes Zoster and Herpes Simplex Treatment, Prevention (Suppression) and Reduction of Transmission: The dosage should be reduced in patients with significantly impaired renal function (see table).

Click on icon to see table/diagram/image

In patients on hemodialysis, the Valtrex dosage recommended for patients with a creatinine clearance (CrCl) of <15 mL/min should be used. This should be administered after the hemodialysis has been performed.
CMV Prophylaxis: The dosage of Valtrex should be adjusted in patients with impaired renal function as follows: CrCl ≥75 mL/min: 2 g 4 times daily; 50 to <75 mL/min: 1.5 g 4 times daily; 25 to <50 mL/min: 1.5 g 3 times daily; 10 to <25 mL/min: 1.5 g twice daily; <10 mL/min or dialysis: 1.5 g once daily.
In patients on hemodialysis, the Valtrex dosage should be administered after hemodialysis has been performed.
The creatinine clearance should be monitored frequently, especially during periods when renal function is changing rapidly eg, immediately after transplantation or engraftment. Dosage should be adjusted accordingly.
Hepatic Impairment: Studies with Valtrex 1-g unit dose show that dose modification is not required in patients with mild or moderate cirrhosis (hepatic synthetic function maintained). Pharmacokinetic data in patients with advanced cirrhosis (impaired hepatic synthetic function and evidence of portal-systemic shunting) do not indicate the need for dosage adjustment; however, clinical experience is limited. For higher dose, ≥4 g/day (see Precautions).