Skip to content

Oral Antivirals for Cold Sores

Font Size

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 Your Dentist Wants You to Do

You probably don't often think of dentistry and sports in the same breath, but Oakland, Calif.-based dentist Eric Yabu, DDS, certainly does. Yabu does double duty as team dentist for the sports medicine program at the University of California, Berkeley, where he's tasked with making custom mouth guards for the athletes as well as providing emergency care. Away from the playing field, Yabu, who is also an assistant clinical professor at the University of California, San Francisco, sees patients of...

Read the What Your Dentist Wants You to Do 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: March 12, 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

sore foot
3 warning signs.
acupuncture needle on shoulder
10 tips to look and feel good.
Epinephrine Injection using Auto-Injector Syringe
Life-threatening triggers.
disciplining a boy
Types, symptoms, causes.
psoriasis
What it looks like.
checking blood sugar
Symptoms and treatment.
man behind computer screen
10 possible causes.
Woman with itchy watery eyes
Common triggers.
man screaming
Making sense of symptoms.
human liver
What puts you at risk?
caregiver with parent
10 tips for daily life.
two male hands
Understanding RA.

Women's Health Newsletter

Find out what women really need.