An open-label, dose escalation pilot study of the effect of clonazepam in burning mouth syndrome

Current treatment for burning mouth syndrome is usually directed at correction of detected organic causes or is empiric, and it often involves the use of tricyclic antidepressants. Recently, there has been renewed interest in the use of benzodiazepines for burning mouth syndrome. The present study was designed to assess the effect of clonazepam in burning mouth syndrome.

Thirty patients, each with a chief complaint of mouth burning without oral mucosal lesions, were entered into the study. All patients underwent routine blood screens. Identified abnormalities were corrected, when possible, before clonazepam was prescribed. The starting dose was 0.25 mg daily, with an increase in dose of 0.25 mg on a weekly basis if symptoms continued.

The subject population consisted of 29 women and 1 man. All subjects had been symptomatic (average premorbid burning intensity, 7.0 +/- 1.9 on 10-point scale) for 1 month to 12 years (mean, 3.9 +/- 3.4 years; median, 2.75 years), and 16% had had burning for more than 2 years. Three groups of patients were identified: those who experienced partial to complete relief with clonazepam and who were using the medication at the last follow-up (group 1; 43%); those who found the clonazepam helpful but withdrew from the medication because of side effects--usually drowsiness (group 2; 27%); and those who did not benefit from clonazepam (group 3; 30%). Among the 3 groups, age was found to be significantly lower for group 1 than for group 2 but not significantly lower for group 1 than for group 3. Although the difference did not reach significance, the mean dose of clonazepam appeared lower for group 1 patients than for the other 2 patient groups. The number of patients with burning for less than 2 years was larger in group 1 than in the other groups.

The results suggest that clonazepam may be helpful in burning mouth syndrome, inasmuch as 70% of patients (groups 1 and 2) experienced pain reduction with effects at low doses. These findings suggest that the mechanism of action of clonazepam may be specific and separate from the anxiolytic effect of the benzodiazepines and that clonazepam may represent a useful therapy in a subset of patients with burning mouth syndrome. Double-blind, placebo-controlled trials are warranted.