Cutaneous application of menthol 10% solution as an abortive treatment of migraine without aura: a randomised, double-blind, placebo-controlled, crossed-over study

Objective: To investigate the efficacy and safety of the cutaneous application of menthol 10% solution for the abortive treatment of migraine. Background: Peppermint and its active ingredient menthol have long been used for the treatment of various pain conditions including headache. Methods: This is a randomised, triple-blind, placebo-controlled, crossed-over study conducted in the neurology Clinic of Nemazee Hospital, affiliated with Shiraz University of Medical Sciences, Shiraz, southern Iran, from March 2007 to March 2008. The patients were recruited via local newspaper advertisements. Eligible patients were categorised into two groups and a 10% ethanol solution of menthol (as drug) and 0.5% ethanol solution of menthol (as placebo) were applied to the forehead and temporal area in a crossover design. Pain free, pain relief, sustained pain free and sustained pain relief end-points were measured by questionnaires using a visual analogue scale. Results: The intent-to-treat population consisted of 35 patients (80% women, 20% men, mean age: 29.6 +/- 6.2) with 118 migraine attacks. In the intent-to-treat population, the menthol solution was statistically superior to the placebo on 2-h pain free (p = 0.001), 2-h pain relief (p = 0.000), sustained pain free and sustained pain relief end-points (p = 0.008). The menthol solution was also more efficacious in the alleviation of nausea and/or vomiting and phonophobia and/or photophobia (p = 0.02). In the per-protocol population, there was significantly higher number of patients who experienced at least one pain free/pain relief after the application of menthol rather than the placebo (p = 0.002). No significant difference was seen between the adverse effects of the drug and the placebo groups (p = 0.13). Conclusion: Menthol solution can be an efficacious, safe and tolerable therapeutic option for the abortive treatment of migraine.