Valacyclovir Dosage

This dosage information may not include all the information needed to use Valacyclovir safely and effectively. See additional information for Valacyclovir.

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Usual Adult Dose for Herpes Simplex Labialis

2 g orally every 12 hours for a total of 2 doses (4 g)
Therapy should be started at the earliest sign of a cold sore (such as tingling, burning, or itching).

Usual Adult Dose for Herpes Simplex - Mucocutaneous/Immunocompetent Host

Genital herpes:
First episode: 1 g orally twice a day for 7 to 10 days
The efficacy has not been established if started more than 72 hours after onset of signs and symptoms.

Recurrent episode: 500 mg orally twice a day for 3 days
Therapy should be started at the first sign of a genital herpes episode. The efficacy has not been established if started more than 24 hours after onset of signs and symptoms.

Usual Adult Dose for Herpes Simplex - Suppression

Chronic suppression of recurrent genital herpes:
Immunocompetent host: 1 g orally once a day
Alternative dose for immunocompetent host with a history of 9 or fewer recurrences per year: 500 mg orally once a day
Safety and efficacy beyond 1 year have not been established in immunocompetent patients.

HIV-infected host with CD4 count 100 cells/mm3 or more: 500 mg orally twice a day
Safety and efficacy beyond 6 months have not been established in HIV-infected patients.

Reduction of transmission of genital herpes in immunocompetent host with a history of 9 or fewer recurrences per year: 500 mg orally once a day for the source partner
Efficacy beyond 8 months has not been established in discordant couples.

Usual Adult Dose for Herpes Zoster

1 g orally every 8 hours for 7 days
Most effective if started within 48 hours of onset of rash. The efficacy has not been established if started more than 72 hours after onset of rash.

Usual Adult Dose for Herpes Simplex - Mucocutaneous/Immunocompromised Host

Genital herpes in HIV-infected host:
First episode: 1 g orally twice a day for 7 to 14 days
The efficacy has not been established if started more than 72 hours after onset of signs and symptoms.

Recurrent episode: 1 g orally twice a day for 5 to 14 days
Therapy should be started at the first sign of a genital herpes episode. The efficacy has not been established if started more than 24 hours after onset of signs and symptoms.

The use of valacyclovir for the treatment of initial and recurrent genital herpes in HIV-infected patients is not approved by the FDA.

Usual Adult Dose for CMV Prophylaxis

In renal transplant recipient: 2 g orally 4 times a day

The use of valacyclovir for cytomegalovirus prophylaxis is not approved by the FDA.

Usual Pediatric Dose for Herpes Simplex Labialis

12 years or older: 2 g orally every 12 hours for a total of 2 doses (4 g)
Therapy should be started at the earliest sign of a cold sore (such as tingling, burning, or itching).

Usual Pediatric Dose for Varicella-Zoster

Chickenpox in immunocompetent host:
2 to less than 18 years: 20 mg/kg orally 3 times a day for 5 days
Maximum dosage: 1 g orally 3 times a day

Therapy should be initiated at the earliest sign of chickenpox, no later than 24 hours after onset of rash.

See Other Comments for extemporaneous preparation of oral suspension.

Renal Dose Adjustments

Adults:
CrCl 30 to 49 mL/min:
Herpes labialis: 1 g orally every 12 hours for a total of 2 doses

Genital herpes:
Initial and recurrent episodes, suppression: Usual dose

Herpes zoster: 1 g orally every 12 hours

CrCl 10 to 29 mL/min:
Herpes labialis: 500 mg orally every 12 hours for a total of 2 doses

Genital herpes:
Initial episode: 1 g orally every 24 hours
Recurrent episodes: 500 mg orally every 24 hours
Suppression in immunocompetent host: 500 mg orally every 24 hours
Alternative dose for suppression in immunocompetent host with 9 or fewer recurrences per year: 500 mg orally every 48 hours
Suppression in HIV-infected host: 500 mg orally every 24 hours

Herpes zoster: 1 g orally every 24 hours

CrCl less than 10 mL/min:
Herpes labialis: 500 mg orally one time

Genital herpes:
Initial and recurrent episodes: 500 mg orally every 24 hours
Suppression in immunocompetent host: 500 mg orally every 24 hours
Alternative dose for suppression in immunocompetent host with 9 or fewer recurrences per year: 500 mg orally every 48 hours
Suppression in HIV-infected host: 500 mg orally every 24 hours

Herpes zoster: 500 mg orally every 24 hours

Pediatric patients:
CrCl less than 50 mL/min: Data not available

Liver Dose Adjustments

No adjustment recommended.

Precautions

Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), including some fatalities, has been reported during clinical trials in patients with advanced HIV disease and in allogeneic bone marrow transplant and renal transplant recipients, who were receiving 8 g valacyclovir per day. Valacyclovir should be discontinued at once if clinical signs, symptoms, and laboratory abnormalities consistent with TTP/HUS occur.

Acute renal failure has been reported in elderly patients (with or without renal dysfunction), patients with underlying renal disease receiving higher doses than recommended for their level of renal function, patients receiving other nephrotoxic drugs, and patients without adequate hydration. Valacyclovir should be used with caution in geriatric patients and in patients receiving concomitant nephrotoxic agents. Dosage reduction is recommended in patients with renal impairment.

Central nervous system (CNS) side effects (including agitation, hallucinations, confusion, delirium, seizures, and encephalopathy) have been reported in patients with or without reduced renal function and in patients with underlying renal disease receiving higher doses than recommended for their level of renal function. CNS side effects are more likely in elderly patients. Valacyclovir should be discontinued if CNS side effects occur.

Acyclovir-resistant isolates of herpes simplex virus (HSV) and varicella-zoster virus (VZV) have been observed, almost exclusively among immunocompromised patients, perhaps in part due to chronic subtherapeutic plasma acyclovir concentrations derived from long-term oral acyclovir therapy. No occurrences of valacyclovir resistance have been reported during clinical trials. However, since high-dose valacyclovir achieves plasma acyclovir concentrations similar to those seen with IV acyclovir, resistance would be expected if there is evidence of resistance to IV acyclovir. These isolates should be anticipated to show resistance to famciclovir and ganciclovir as well, but may be susceptible to vidarabine or foscarnet.

Safety and efficacy of valacyclovir have not been established for suppression of genital herpes in patients with advanced HIV disease (CD4+ cell count less than 100 cells/mm3), for treatment of genital herpes in HIV-infected patients, for treatment of disseminated herpes zoster, or for reducing transmission of genital herpes in patients with multiple partners or nonheterosexual couples.

There are no data on valacyclovir treatment initiated more than 72 hours after onset of the zoster rash. Patients should be advised to start therapy as soon as possible after diagnosis of herpes zoster.

There are no data on the efficacy of valacyclovir treatment initiated more than 72 hours after onset of signs and symptoms of a first episode of genital herpes or more than 24 hours after onset of signs and symptoms of a recurrent episode. Patients should be advised to start therapy at the first sign or symptom of an episode.

There are no data on the efficacy of valacyclovir treatment initiated after clinical signs of a cold sore (e.g., papule, vesicle, or ulcer) develop. Patients should be advised to start therapy at the earliest symptom of a cold sore (e.g., tingling, itching, or burning). Treatment for herpes labialis should not exceed 1 day.

There are no data of the efficacy or safety of chronic suppression for more than 1 year in healthy patients or for more than 6 month in HIV-infected patients. The efficacy for the reduction of transmission of genital herpes has not been established beyond 8 months in discordant couples.

Patients should be advised that valacyclovir is not a cure for genital herpes or herpes labialis and does not reduce transmission of other sexually transmitted infections.

Safety and efficacy have not been established in patients 18 years of age or older with chickenpox. Safety and efficacy have not been established in pediatric patients less than 18 years of age with genital herpes or herpes zoster, in patients less than 12 years of age with cold sores, in patients less than 2 years of age with chickenpox, or in pediatric patients requiring suppressive treatment after neonatal herpes simplex virus infection.

Dialysis

About one-third is removed by dialysis during a 4-hour hemodialysis session. Patients should receive the recommended dose after hemodialysis. Supplemental doses should not be required following chronic ambulatory peritoneal dialysis and continuous arteriovenous hemofiltration/dialysis.

Other Comments

Valacyclovir may be given without regard to meals.

Patients should be advised to maintain adequate hydration while taking valacyclovir.

Extemporaneous preparation of oral suspension (25 mg/mL or 50 mg/mL):
1. Prepare Suspension Structured Vehicle USP-NF (SSV) according to USP-NF.
2. Using a pestle and mortar, grind 5 valacyclovir caplets for 25 mg/mL suspension or 10 valacyclovir caplets for 50 mg/mL suspension until a fine powder is produced.
3. Gradually add approximately 5 mL aliquots of SSV to mortar and triturate powder until paste has been produced ensuring the powder has been adequately wetted.
4. Continue to add approximately 5 mL aliquots of SSV to mortar 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.
5. Transfer mixture to suitable 100 mL measuring flask.
6. Transfer cherry flavor (add amount as instructed by suppliers of cherry flavor) to mortar and dissolve in approximately 5 mL SSV. Once dissolved, add to measuring flask.
7. Rinse mortar at least 3 times with approximately 5 mL aliquots of SSV, transferring the rinsing to measuring flask between additions.
8. Add SSV until suspension volume is 100 mL and shake thoroughly to mix.
9. Transfer suspension to an amber glass bottle with a child-resistant closure.

The prepared suspension should be shaken well before each dose and stored in a refrigerator. It should be discarded after 28 days.

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