[Subcutaneous histamine in migraine prophylaxis. Initial effects and long-term outcome].
INTRODUCTION: Histamine may prove to be effective in migraine prophylaxis, as an specific treatment aimed to limit excessive inflammatory responses involved in the pathophysiology of migraine. METHODS: One hundred and ten migraine patients were selected. The variables analyzed were: a) frequency; b) intensity; c) duration, and d) number of analgesic tablets. Treatment consisted of a regimen of subcutaneous histamine (10 ng/ml of Evan's solution) twice a week, with an administration volume of 1 ng (0.1 ml) of histamine, which was consecutively increased until reaching 10 ng (1 ml); during twelve month. At the end of treatment, the patients remained under observation for 8 years. A Friedman repeated measures ANOVA on ranks test was used to evaluate the statistical significance of differences between basal values and values found. RESULTS: The statistical analysis showed significant differences between basal values and values found for the 3, 6 and 12 months of treatment with histamine (p < 0.0001). The beginning of the 4th week there was a significant decrease in the magnitude of all variables studied (p < 0.0001). During the first and second year after treatment there were no headache attacks. In the third year migraine appeared again same to basal values. CONCLUSIONS: The present study provides evidence of the safety and efficacy of histamine, applied subcutaneously at doses of 1 to 10 ng twice a week, bringing about a new therapeutic alternative and laying the clinical and pharmacological groundwork for the use of histaminergic H3-agonists in migraine prophylaxis.