Cold sore is caused by herpes simplex virus (HSV) infections: HSV-1 and HSV-2. HSV-1 is commonly transmitted via saliva and causes the majority of cold sore infections. After you are infected the first time, the virus lies dormant in your body and can reactivate to cause recurrent outbreaks in 20-40% of patients. Cold sore is also known as fever blisters or herpes labialis. It is estimated that up to 80% of adolescents and adults have been exposed to HSV-1 virus. The HSV-1 virus spreads by intimate oral to oral contact and via contact with the virus in sores, saliva and surfaces in and around the mouth. It may also spread through cosmetics, razors, towels or eating utensils.
Antiviral treatment for cold sores
The infection generally resolves on its own in patients that do not have a compromised immune system, but antiviral medications may be used for treatment to reduce the duration and severity of the infection. For pain relief, you can use acetaminophen (Tylenol), ibuprofen (Advil) or naproxen (Aleve) if needed.
Oral antiviral treatment for cold sore includes acyclovir, famciclovir and valacyclovir. Treatment should be started as soon as possible for it to be effective, ideally within 48 hours. Acyclovir, famciclovir and valacyclovir have been shown to decrease time to lesion healing and duration of symptoms by 1–2 days in randomized controlled trials.
Acyclovir for cold sore treatment: Acyclovir (Zovirax) has been shown to decrease the duration of symptoms and viral shedding in a clinical trial in children.[Ref] It is generally very well tolerated. A typical treatment course is acyclovir 5 times a day for 5-7 days. Acyclovir is also available as a acyclovir 5% cream, evidence supports to use of the cream however, it may be less effective than oral antiviral medications.
Valacyclovir for cold sore treatment: Valacyclovir (Valtrex) has been shown in trial to reduce the time to healing and pain resolution more effectively than acyclovir for recurrent infections.[Ref] Valacyclovir is preferred over acyclovir due to shorter duration of treatment and less frequent dosing required. A typical treatment course of valacyclovir for cold sore treatment is 1 g twice daily for 7 days for the first infection and then 2g twice daily for 1 day for recurrent infections. Valacyclovir is generally very well tolerated.
Famciclovir for cold sore treatment: Famciclovir (Famvir) has been shown to reduce the time it takes for the lesion to heal and decrease duration of symptoms.A typical treatment course of famciclovir is 500 mg twice daily for 7 days for the first infection and then 750 mg twice daily for 1 day or 1500 mg as a single dose for recurrent infection. Famciclovir is generally very well tolerated.
Abreva for cold sore treatment: Abreva has active ingredient Docosanol and is a topical treatment for cold sore. It is available over the counter, unlike oral antiviral medications that need a prescription from the doctor. Abreva should be applied 5 times daily at the first sign of cold sore such as pain, itching, burning, redness or tingling. Study comparing Abreva to placebo showed that patients taking Abreva healed 17 hours sooner and stopped discomfort 12 hours faster. [Ref]
Disclaimer: We have made every effort to ensure that all information is factually correct and up to date, however this article is not comprehensive and does not contain all relevant information about the topic. IT should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should consult your doctor or pharmacist before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.