Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

valacyclovir (Rx)Brand and Other Names:Valtrex

 
 
 

Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

tablet

  • 500mg
  • 1g
more...

Herpes Labialis

2 g PO q12hr for 1 day

Herpes Zoster

1 g PO q8hr for 7 days (no data on efficacy if started 72 hours after rash)

Genital Herpes

Initial episode: 1 g PO q12hr for 10 days

Recurrent episodes: 500 mg PO q12hr for 3 days (no data on efficacy if started >24 hours after lesion onset)

Suppressive therapy (immunocompetent patients): 1 g/day PO

Suppressive therapy (immunocompetent patients with ≤9 recurrences annually): 500 mg/day PO; transmission reduction for source partner, 500 mg/day PO

Suppressive therapy (HIV-infected patients): 500 mg PO q12hr

Dosing Modifications

Herpes labialis

  • CrCl 30-49 mL/min: 1 g PO q12hr for 1 day
  • CrCl 10-29 mL/min: 500 mg PO q12hr for 1 day
  • CrCl <10 mL/min: 500 mg PO once

Herpes zoster

  • CrCl 30-49 mL/min: 1 g PO q12hr
  • CrCl 10-29 mL/min: 1 g/day PO
  • CrCl <10 mL/min: 500 mg/day PO

Genital herpes (initial episode)

  • CrCl 10-29 mL/min: 1 g/day PO
  • CrCl <10 mL/min: 500 mg/day PO qDay

Genital herpes (recurrent episodes)

  • CrCl ≤29 mL/min: 500 mg/day PO

Genital herpes (suppressive therapy, immunocompetent patients)

  • CrCl ≤29 mL/min: 500 mg/day PO

Genital herpes (suppressive therapy, immunocompetent patients with ≥9 recurrences annually)

  • CrCl ≤29 mL/min: 500 mg PO q48hr

Genital herpes (suppressive therapy, HIV-infected patients)

  • CrCl ≤29 mL/min: 500 mg/day PO

Dosage Forms & Strengths

tablet

  • 500mg
  • 1g
more...

Chickenpox

<2 years: Safety and efficacy not established

>2 years: 20 mg/kg PO q8hr for 5 days; not to exceed 1 g PO q8hr 

Herpes Labialis

<12 years: Safety and efficacy not established

>12 years: 2 g PO q12hr for 1 day

Monitor renal function; dosage may have to be adjusted, depending on renal status

Next

Interactions

Interaction Checker

valacyclovir and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            Sort by :  
             activity indicator 
            Previous
            Next

            Adverse Effects

            >10%

            Headache (14-35%)

            Neutropenia (<18%)

            Elevated aspartate transaminase (AST) (2-16%)

            Nasopharyngitis (<16%)

            Nausea (6-15%)

            Elevated alanine transaminase (ALT) (<14%)

            Abdominal pain (2-11%)

            1-10%

            Dysmenorrhea (1-8%)

            Depression (<7%)

            Arthralgia (<1-6%)

            Vomiting (<1-6%)

            Dizziness (2-4%)

            Rash (≤8%)

            Rhinorrhea (<2%)

            Thrombocytopenia (<3%)

            Leukopenia (≤1%)

            <1%

            Agitation

            Aggression

            Alopecia

            Confusion

            Erythema multiforme

            Hypertension

            Tachycardia

            Tremor

            Visual disturbances

            Previous
            Next

            Warnings

            Contraindications

            Hypersensitivity to valacyclovir or acyclovir

            Cautions

            Thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS) reported in patients with advanced HIV disease and in allogenic bone marrow transplant and renal transplant recipients

            Acute renal failure (ARF) may occur, especially in elderly patients or those with underlying renal impairment receiving higher than recommended doses; use with caution in patients with renal impairment, the elderly, and/or patients receiving nephrotoxic drugs

            Treatment should begin with the earliest symptom (tingling, burning, itching) in cold sores; for genital herpes, it should begin at the first signs and symptoms (within 72 hours of onset of first diagnosis or 24 hours of onset of recurrent episodes); for herpes zoster, it should begin within 72 hours of onset of rash; for chicken pox, it should begin with the earliest sign or symptom

            Central nervous system (CNS) effects may occur (eg, agitation, hallucinations, confusion, encephalopathy); risk of CNS adverse effects is higher in elderly patients

            Adequately hydrate patient; decreased precipitation in renal tubules may occur

            Previous
            Next

            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Drug excreted in breast milk; use with caution

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

            more...
            Previous
            Next

            Pharmacology

            Mechanism of Action

            Converted to acyclovir by intestinal and hepatic metabolism

            Competes with deoxyguanosine triphosphate for viral DNA polymerase to inhibit DNA synthesis and viral replication

            Absorption

            Rapidly absorbed

            Bioavailability: ~55% (after conversion to acyclovir)

            Distribution

            Acyclovir (active drug) is widely distributed throughout the body, including brain, kidney, muscle, uterus, lungs, liver, spleen, vagina, and cerebrospoinal fluid (CSF)

            Protein bound: 13.5-17.9%

            Metabolism

            Metabolized by liver; valacyclovir is rapidly and nearly completely converted to acyclovir and L-valine via first-pass effect; acyclovir is hepatically metabolized to a very small extent by aldehyde oxidase and by alcohol and aldehyde dehydrogenase (inactive metabolites)

            Elimination

            Half-life (normal renal function, adults): Acyclovir, 2.5-3.3 hr; valacyclovir, ~30 min

            Half-life (end-stage renal disease): Acyclovir, 14-20 hr

            Excretion: Urine (89%), feces (minimal)

            Previous
            Next

            Images

            Previous
            Next

            Formulary

            FormularyPatient Discounts

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Add or Remove Plans
            Plans for
            Select State:
            Non-Medicare PlansMedicare Plans

            Select a box to add or remove a plan.

            Select a class to view formulary status for similar drugs

            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
             
             
             
            All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.