Valtrex Dosage/Direction for Use

Adults: Treatment of herpes zoster (shingles) including ophthalmic zoster: The dosage is 1000 mg of Valaciclovir (Valtrex) to be taken three times daily for seven days.
Treatment of herpes simplex infections: Immunocompetent adults and adolescents (12 years and older): The dosage is 500 mg of Valaciclovir (Valtrex) to be taken twice daily.
For recurrent episodes, treatment should be for three or five days. For initial episodes, which can be more severe, treatment may have to be extended from five days to ten days. Dosing should begin as early as possible. For recurrent episodes of herpes simplex, this should ideally be during the prodromal period or immediately the first signs or symptoms appear. Valaciclovir (Valtrex) can prevent lesion development when taken at the first signs and symptoms of an HSV recurrence.
Alternatively, for herpes labialis (cold sores), Valaciclovir (Valtrex) 2 g twice-daily for one day is effective treatment. The second dose should be taken about 12 hours (no sooner than 6 hours) after the first dose. When using this dosing regimen, treatment should not exceed one day, since this has been shown not to provide additional clinical benefit. Therapy should be initiated at the earliest symptom of a cold sore (e.g. tingling, itching or burning).
Prevention (suppression) of recurrences of herpes simplex infections: Immunocompetent adults and adolescents (12 years and older): In immunocompetent patients, 500 mg of Valaciclovir (Valtrex) to be taken once daily.
Some patients with very frequent recurrences (e.g. 10 or more per year) may gain additional benefit from the daily dose of 500 mg being taken as a divided dose (250 mg twice daily).
Immunocompromised adults: For immunocompromised patients the dose is 500 mg twice daily.
Reduction of transmission of genital herpes: In immunocompetent heterosexual adults with 9 or fewer recurrences per year, 500 mg of Valaciclovir (Valtrex) to be taken once daily by the infected partner.
There are no data on the reduction of transmission in other patient populations.
Prophylaxis of cytomegalovirus (CMV) infection and disease: The dosage of Valaciclovir (Valtrex) in adults and adolescents (from 12 years of age) is 2 g four times a day, to be initiated as early as possible post-transplant. This dose should be reduced according to creatinine clearance (see Renal Impairment as follows).
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 Valaciclovir (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 as follows).
Adequate hydration should be maintained.
Renal impairment: Caution is advised when administering valaciclovir to patients with impaired renal function. Adequate hydration should be maintained.
The dosage of Valaciclovir (Valtrex) should be reduced in patients with significantly impaired renal function as shown in the table as follows: See table.

Click on icon to see table/diagram/image

In patients on intermittent haemodialysis, the Valaciclovir (Valtrex) dosage recommended for patients with a creatinine clearance of less than 15 mL/min should be used. This should be administered after the haemodialysis has been performed.
The creatinine clearance should be monitored frequently, especially during periods when renal function is changing rapidly, e.g. immediately after transplantation or engraftment. The Valaciclovir (Valtrex) dosage should be adjusted accordingly.
Hepatic Impairment: Studies with a 1 g unit dose of Valaciclovir (Valtrex) 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 doses (4 g or more/day), see Precautions.