In July 2000, following clinical trials, docosanol (doe-KOE-suh-nawl) was approved by the US Food and Drug Administration for the treatment of recurrent oral and facial herpes simplex virus (HSV). Marketed under the brand name Abreva, docosanol is available over the counter as a 10% cream in either a tube or a pump.
Abreva is labeled for use on recurrent oral-facial HSV (cold sores). It is not approved for use in genital herpes.
Docosanol is a saturated 22-carbon aliphatic alcohol that occurs naturally in the surface layers of leaves, fruits, and vegetables. It is also a component of some brands of policosanol, a generic name for an extract derived from sugar cane stems, rice bran, and other plant waxes. Rice bran is particularly rich in docosanol.
When applied at the first sign of symptoms (burning, itching, tingling, or pain), and when used five times daily for the duration of an outbreak, Abreva leads to healing of viral lesions about one day earlier than untreated lesions. Furthermore, treatment with docosanol leads to a statistically significant reduction in the duration of symptoms associated with a herpes outbreak.
Docosanol’s (Abreva’s) Mechanism of Action
- Docosanol appears to inhibit the fusion of the herpes virus to human cells, thus limiting viral replication. Studies have shown this same effect with other enveloped viruses (those with a lipid covering), such as respiratory syncytial virus.
- Docosanol, a highly lipophilic molecule, apparently interacts with cellular membranes in such a way that viral entry into cells is markedly reduced or prevented. Optimal antiviral activity is achieved when cells have experienced a period of incubation with docosanol prior to exposure to viruses—reinforcing the need to begin treatment with Abreva at the first sign of HSV outbreak.
- Notably, since docosanol does not seem to interfere with the replication of viral nucleic acid, the likelihood of contributing to the development of resistant viral strains is low.
(Adapted from Katz DH, et al. Antiviral activity of 1-docosanol, an inhibitor of lipid-enveloped viruses including herpes simplex. Proc Natl Acad Sci USA 1991;88:10825-10829)
Side Effects of Abreva (Docosanol)
- The most commonly reported side effect for Abreva is headache, but this complaint was no more common among those people using the medication than those in placebo groups. Other side effects include burning, redness, itching, or stinging at the site of application, and some users have reported increased acne.
- While docosanol hasn’t caused birth defects in animal studies, women who are pregnant should consult their physician before using Abreva. It isn’t known if Abreva is excreted in breast milk.
Abreva (Docosanol): The Big Picture
While Abreva (docosanol) may lessen the duration and discomfort of recurrent herpes outbreaks, the benefit is not marked. During the early days of its marketing, consumers were misled to believe that Abreva “cut the healing time for cold sores in half.” Settlement of a class-action suit filed in April 2002 brought advertising into line with more realistic expectations for this medication. (California court upholds settlement of class action over cold sore medication. Pharmaceutical Law and Industry 2007;5(13):325)
Further research may reveal some uses for docosanol in the treatment of illness caused by other enveloped viruses, such as influenza (including H5N1).
Stephen Allen Christensen - Dr. Steve Christensen's writing has appeared in magazines, professional journals, poetry anthologies, and children's books since 1976.
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