Fever blisters--also called cold sores--are skin lesions produced by an oral infection with the herpes simplex virus. The American Social Health Association reports that up to 90 percent of 50-year-olds carry the virus, and that approximately one-third experience episodic recurrences. Although there is no cure for fever blisters, the Food and Drug Administration has approved several drugs that decrease the severity and duration of lesions.
Oral Prescription Medications
Oral prescription medications used to treat fever blisters include acyclovir, valacyclovir and famciclovir. While all of the drugs belong to the same family of antiviral drugs; they differ in effectiveness and dosing schedules. A 1997 study in the "British Medical Journal" found that acyclovir taken five times per day for five days reduced the healing time of first-time fever blisters by more than half--from nine days to four--when compared to placebo. Valacyclovir and penciclovir, by comparison, are taken for a single day and result in a one- to two-day decrease in the duration of fever blisters.
Prescription Topical Medications
The Food and Drug Administration has approved two prescription topical medications for the treatment of fever blisters, penciclovir and acyclovir. Patients should apply penciclovir cream every two hours while awake and acyclovir cream five times a day, each for four days. According to a 2008 report in the "Archives of Internal Medicine," topical medications for fever blisters do not work as effectively as oral medications. Doctors may reserve these drugs for patients who experience severe side effects from oral doses.
Non-Prescription Topical Medications
Non-prescription topical medications for the treatment of fever blisters are marketed under several different brand names, including Abreva, Lysine+, Herpecin-L, Blistex Medicated, Orajel, Releev and others. Of these, the FDA allows only one, Abreva, to claim a reduction in healing time. The active ingredient in Abreva is a fatty alcohol called docosanol. The authors of a 2010 review in the journal "Expert Opinions in Pharmacotherapy" concluded that products containing docosanol represent a good choice for patients who experience resistance or intolerance to prescription antiviral drugs because they inhibit viral replication by a different mechanism.
References
- American Social Health Association: Learn About Herpes: Oral Herpes
- "British Medical Journal"; Treatment of herpes simplex gingivostomatitis with aciclovir in children: a randomised double blind placebo controlled study; J. Amir, L. Harel, Z. Smetana, and I.Varsano; 1997
- "Archives of Internal Medicine"; The Treatment of Herpes Simples: An Evidence-Based Review; C. Cernik, K. Gallina, and R.T. Brodell; June 2008
- "Expert Opinions in Pharmacotherapy"; Topical n-docosanol for management of recurrent herpes labialis; N.S. Treister and S.B. Woo; April 2010
