Is there an effective pharmacological treatment in the prevention of vasovagal syncope?

Many studies have claimed successful pharmacological prevention of vasovagal syncope in open formats with a wide variety of drugs. However, when therapy has been subjected to clinical trial to date no drug has shown any real benefit but it is necessary to add that the means of assessment leave much to be desired. These are repeat tilt testing, reported symptoms, analysis of syncopal burden in a population and time to syncopal recurrence. The disadvantages of any parameter derived from tilt testing is that its reproducibility is open to question and other aspects such as tilt duration before syncope have been inadequately investigated. With respect to symptom recurrence there are limitations because of the well known occurrence of vasovagal syncope in clusters and the long trial time that it is necessary because of relatively infrequent attacks. Furthermore, there is a placebo effect of the investigation of syncope which may delay the first recurrence. The first large trial is now underway and it is hoped that it may offer a method of prevention of vasovagal syncope which is both effective and acceptable.