NEW YORK, May 06 (Reuters) -- An antiviral cream is the first to speed the healing of cold sores, researchers say.
Penciclovir cream was recently approved in the U.S. for use on cold sores caused by herpes simplex virus. In a study, the antiviral cream was tried by 782 people with a history of at least three herpes cold sore outbreaks a year. They used the cream within the first hour of cold sore symptoms, and continued to apply it every two hours while awake. Cold sores healed an average of one day faster using the cream compared with patients who used a placebo (inactive) cream.
Study patients treated with penciclovir healed after about 4.8 days versus 5.5 days for those applying the placebo cream.
The penciclovir cream also reduced the number of days when the patients felt pain from the cold sores -- patients using the antiviral cream reported an average of 3.5 days of painful sensation versus 4.1 days reported by those using the placebo cream.
"Some patients may have experienced a greater benefit than others, for example, those with more severe lesions," say researchers for the University of Utah School of Medicine in Salt Lake City.
According to the investigators, the faster healing time found in the study "may appear modest." But they point out that participants included patients who did not always use the new cream as prescribed, and thus may have received little overall benefit from it, "and whose inclusion in the data may have reduced the overall benefit attributable to penciclovir."
More than 80% of patients applied the medication or placebo at least six times on each of the four study days.
But the researchers were surprised to find that people who began using the cream late in their cold sore outbreak also "experienced statistically significant improvements in lesion healing and pain resolution attributable to treatment with penciclovir cream."
Cold sores were swabbed for laboratory study to look for virus particles twice during the study. Patients using penciclovir stopped "shedding" virus significantly faster than those who received the placebo cream, reducing the time that they were infectious to others.
"The positive outcome of the study provides conclusive evidence that herpes labialis (cold sores) is a treatable disease and should encourage continued clinical research on topical (applied to the skin), and systemic (taken internally) antiviral therapies for this common, recurrent infection," the researchers conclude.
SOURCE: The Journal of the American Medical Association (1997;277:1374-1379)
