In the 2008 edition of "Harrison's Principles of Internal Medicine," Dr. Lawrence Corey, professor of infectious diseases at the University of Washington, explains that up to 90 percent of the population is infected with the herpes simplex virus that causes cold sores. Most people experience symptoms so mild that they go unrecognized, while about a third experience the painful skin lesions known as cold sores. On July 25, 2000, the Food and Drug Administration approved Abreva, an over-the-counter antiviral medication for cold sores.
Function
The active ingredient in Abreva is a 22-carbon fat-containing alcohol also known as docosanol, n-docosanol, behenyl alcohol and benzyl alcohol. In the 2008 edition of "Basic and Clinical Pharmacology," Dr. Sharon Safrin, professor at the University of California-San Francisco, says that docosanol bathes the cell membranes and prevents the herpes simplex virus from crossing and infecting the cells. Although docosanol prevents the herpes simplex virus from infecting new cells, it does not kill the virus, and it does not prevent cold sores from recurring at a later date.
Recommended Uses
According to Abreva maker GlaxoSmithKline, Abreva is the only over-the-counter medication that is FDA approved to reduce the duration and severity of cold sores. In addition, unlike prescription antiviral drugs, Abreva reduces pain and itching caused by cold sores. Abreva is not for cold sores inside the mouth or nose. Children under 12 and women who are pregnant or nursing should talk to their doctors about using Abreva, because the safety of the medication has not been evaluated in these groups.
Application
Someone using Abreva should apply it as soon as he suspects that he is developing a cold sore, according to Abreva.com. The website recommends that the cream be applied in a quantity sufficient to cover the cold sore and then gently massage in until the medication is completely absorbed. This should be repeated five times per day --- every three to four hours during waking hours --- for up to 10 days or until the cold sore resolves. In addition, Abreva.com advises handwashing before application to reduce the risk of a secondary bacterial infection. Handwashing after application reduces the risk of spreading the virus to other people or other sites on the body.
Safety
The active ingredient in Abreva, docosanol, is commonly used in cosmetics and other personal-care products, so it's generally well tolerated. Safrin reports that about 10 percent of those who use Abreva complain of headaches. A smaller number --- about 2 percent --- report skin reactions such as acne, redness, dryness, swelling, flaking, itching or burning. Those who experience severe symptoms or symptoms that worsen over time should stop using Abreva and contact their doctors for instructions.
Effectiveness
In the April 2010 edition of "Expert Opinions in Pharmacotherapy," Harvard oral surgeons Nathaniel S. Treister and Sook-Bin Woo report that clinical studies show that Abreva is as effective as prescription topical antiviral medications but less effective that prescription oral antiviral medications. Started within 48 hours of symptom onset, Abreva heals cold sores, on average, one day faster than no medication at all, Treister and Woo say.
References
- "Harrison's Principles of Internal Medicine, 23rd Edition"; Anthony S. Fauci, M.D. et al.; 2008
- "Basic and Clinical Pharmacology, 11th Edition"; Bertram G. Katzung, M.D., Ph.D. et al.; 2008
- "Expert Opinions in Pharmacotherapy"; Topical N-Docosanol for Management of Recurrent Herpes Labialis; Nathaniel S. Treister, D.M.D. and Sook-Bin Woo, D.M.D., M.M.Sc.; Apr. 2010
- GlaxoSmithKline.com: Consumer Health Care: Abreva
- Abreva.com: Abreva Frequently Asked Questions
