April 23 (HealthDay News) -- The drug pentoxifylline offers only limited benefit for treating one form of mouth ulcers, while a cream commonly used to treat eczema appears effective in treating another kind, according to two studies published in the April issue of the journal Archives of Dermatology.

In the first study, British researchers at the University of Sheffield found that pentoxifylline provided limited benefit to patients with mouth ulcers due to recurrent aphthous stomatitis, which is characterized by recurring mouth ulcers in otherwise healthy people. The condition affects about 20 percent of the population.

The 60-day study included 26 people, average age 33, who took either one 400-milligram tablet of pentoxifylline three times a day or three placebo pills per day.

"Patients taking pentoxifylline had less pain and reported smaller and fewer ulcers compared with baseline," the study authors wrote. "Patients taking placebo reported no improvement in these variables. Patients taking pentoxifylline also reported more ulcer-free days than those taking placebo. However, the differences were small and, with the exception of median ulcer size, did not reach statistical significance."

Sixty days after they stopped taking the drug, all patients reported ulcers similar to those they had before the start of the trial. Dizziness, headaches, stomach upset, and increased heart rate were among the side effects reported by those who took the drug.

"Pentoxifylline did not prevent the ulcer episodes from occurring or result in a long-term cure. Thus, given the potential for significant adverse effects and the small benefits of the drug demonstrated in this clinical trial, we cannot recommend pentoxifylline as the drug of first choice for treatment of recurrent aphthous stomatitis, although it may have a second-line role in the management of patients unresponsive to other treatments or as an adjunct to other treatments," the researchers concluded.

The second study found that one percent pimecrolimus cream was effective against oral erosive lichen planus, a severe inflammatory condition that causes painful mouth ulcers. People with the condition, which affects about one percent of the population, may even lose weight because of the mouth pain they experience when eating.

The study, by French researchers at the University of Nice, included six patients who applied pimecrolimus cream on mouth sores twice a day for four weeks and six patients who applied a placebo cream without any active ingredient.

The patients were assessed at the start of the study and again at 14 and 28 days. After 28 days, the average clinical score in the pimecrolimus group decreased from 6.83 to 3.33 and from 4.67 to 3.33 in the placebo group. There were few side effects in either group.

"In the pimecrolimus group, all the patients but one reported a moderate to important improvement of their symptoms and were satisfied by the treatment. This improvement was observed from the first week of treatment, usually within the first two days, and most notably, patients reported less pain when eating," the study authors wrote.

However, all the patients who improved during the study had a relapse within a month after treatment.

Larger studies are needed to better evaluate the safety and efficacy of pimecrolimus cream compared to other treatments, the authors wrote.

SOURCE: JAMA/Archives journals, news release, April 16, 2007