Resumen de Placebo effect in migraine clinical trials
A new drug development is undoubtedly a slow and hard process that demands a commitment of the pharmaceutical industry, with an important human, technological and financial effort. Nowadays, and during the last decades is not enough to "believe" in the effectiveness of a drug. It is necessary to prove it.
In this context clinical trials became an angular stone. In general sense, clinical trials do not present absolute results but instead they give us relative information about drug effectiveness. The use of placebos in clinival research repesents the need of a reference point, against which we will compare the experimental drug results.
This study aimed to characterize the placebo effect in migraine clinical trials and to analyse the impact of methodological and external factors in the placebo effect dimension.
Several meta-analysis were conducted in order to determine the placebo effect in acute migraine clinical trials and in migraine profilaxis clinical trials, globaly and according with specific methodological factors as study design (paralel versus cross-over); drug administration route (oral; parenteral; intranasal) and countries included in the study (Europe versus North America).
Computer based information searches were conducted on the Medline database.
Meta-analysis were computed using Mantel-Haenszel's technique. In acute migraine 98 clinical trials were analysed. In these trials 28.6% of the patients in plabo groups had improved after 2 hours , and 8.8% were pain-free.
The percentage of patients (in placebo groups) who reported adverse events was 23%. In migraine profilaxis 32 clinical trials were included. In placebo groups the reduction in the monthly frequency of migraine attacks was 21% and 30% of those patients reported adverse events.
In actute migraine clinical trials, injectable placebo was more effective, in pain free outcome, than oral or intra nasal placebo. However, patients on injectable placebo reported sig
