Skip to content

    Oral Antivirals for Cold Sores

    Font Size
    A
    A
    A

    Topic Overview

    Most cold sores heal on their own without prescription medicines. But some antiviral medicines (such as acyclovir or famciclovir) when taken orally (tablets) may be helpful in reducing the frequency and severity of attacks of cold sores.

    Doctors may prescribe oral antiviral medicines that can be taken daily to prevent future outbreaks of cold sores. These medicines may also be given during periods of increased risk of getting cold sores (such as during cosmetic surgery or sun exposure).

    Recommended Related to Oral Health

    What Causes Bad Breath?

    Come on, admit it. You’ve suffered from bad breath. Everyone has. It’s one of life’s most common annoyances. The good news is we can do something about it. But first, you need to know where it comes from.

    Read the What Causes Bad Breath? article > >

    Oral antivirals work best in treating recurring cold sores if they are taken within 24 to 48 hours of an outbreak of cold sores.

    Pregnant or nursing women should seek their doctors' advice prior to taking antiviral medicines. Those with kidney problems may be advised to take lower doses.

    Some examples of oral antiviral medicines prescribed to treat cold sores include the following:

    Acyclovir

    Acyclovir (Zovirax) tablets may slightly shorten the duration of pain and the healing time of a first attack of cold sores.1

    Common side effects of acyclovir tablets include nausea, diarrhea, and headache.

    A lower dose of oral acyclovir is needed for people who have reduced kidney function.

    Famciclovir

    Famciclovir (Famvir) is sometimes used to treat the herpes virus that causes cold sores and genital herpes (as well as the virus that causes shingles). This medicine is available only by prescription and is taken orally in tablet form.

    If you are pregnant or nursing, you should talk with your doctor before taking famciclovir.

    This medicine is not recommended for people who have had an allergic reaction to it in the past.

    Possible mild side effects include itching, fever, headache, fatigue, nausea, or diarrhea.

    Valacyclovir

    Valacyclovir (Valtrex) capsules are available by prescription only. It is absorbed by the body much better than some other antiviral medicines (such as acyclovir).

    Possible side effects include skin rash, allergic reaction, headache, dizziness, insomnia, and fatigue.

    Children, pregnant women, and people who have HIV or who have had bone marrow or kidney transplants should talk with their doctors before taking this medicine.

    1

    WebMD Medical Reference from Healthwise

    Last Updated: June 04, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    Next Article:

    Oral Antivirals for Cold Sores Topics

    Hot Topics

    WebMD Video: Now Playing

    Click here to wach video: Dirty Truth About Hand Washing

    Which sex is the worst about washing up? Why is it so important? We’ve got the dirty truth on how and when to wash your hands.

    Click here to watch video: Dirty Truth About Hand Washing

    Popular Slideshows & Tools on WebMD

    disciplining a boy
    Types, symptoms, causes.
    fruit drinks
    Eat these to think better.
    embarrassed woman
    Do you feel guilty after eating?
    diabetes supply kit
    Pack and prepare.
    Balding man in mirror
    Treatments & solutions.
    birth control pills
    Which kind is right for you?
    Remember your finger
    Are you getting more forgetful?
    acupuncture needle on shoulder
    10 tips to look and feel good.
    Close up of eye
    12 reasons you're distracted.
    woman biting a big ice cube
    Habits that wreck your teeth.
    pacemaker next to xray
    Treatment options.
    Pink badge on woman chest to support breat cancer
    Myths and facts.

    Women's Health Newsletter

    Find out what women really need.