Lack of efficacy of alpha-lipoic acid in burning mouth syndrome: a double-blind, randomized, placebo-controlled study.Eur J Pain 2009; 13(5):492-6EJ
A systematic review from the Cochrane Collaboration stated that alpha-lipoic acid (ALA) may help in the management of burning mouth syndrome (BMS). Because all of the data on ALA came from a single group, it has been stressed that its effectiveness should be reproduced in other populations.
A double-blind, randomized, placebo-controlled study, including two test groups (Group A and Group B) and one control group (Group C), was carried out to evaluate the efficacy of systemic ALA (400 mg) and ALA (400 mg) plus vitamins in the treatment of BMS.
Sixty-six patients (54 females and 12 males) were included in an 8-week trial. Symptoms were evaluated by using a visual analogue scale (VAS) and the McGill Pain Questionnaire (MPQ) at 0, 2, 4, 8 and 16 weeks.
Fifty-two patients (43 females and 9 males, aged 67.3+/-11.9 years) completed the study. All three groups had significant reductions in the VAS score and in the mixed affective/evaluative subscale of the MPQ; the responders' rate (at least 50% improvement in the VAS score) was about 30%. No significant differences were observed among the groups either in the response rate or in the mean latency of the therapeutic effect.
The fairly high placebo effect observed is very similar to data obtained from patients affected by atypical facial pain. This study failed to support a role for ALA in the treatment of BMS, and further investigations are needed to identify the cause of BMS in order to develop efficacious therapies.