Placebo in the evaluation of antiulcer drugs

According to the most recent definition, "placebo" is any substance devoid of specific activity, which nevertheless is given in order to obtain an effect. It is used to advantage in identifying active drugs (controlled clinical trials). It has an effect which is usually (though not always) favourable and has its own pharmacology closely resembling that of active substances. In view of the consistency of the placebo effect, any substance tried in the treatment of the various diseases of the alimentary tract must prove superior to placebo in order to be considered an "active" substance. It is only on the basis of this criterion that we may accept the risk of side-effects which, though they may be slight, are nevertheless unjustified if the drugs we are administering are inactive. This drug vs placebo comparison classically takes the form of so-called "double-blind" controlled studies, but for digestive diseases these are far less numerous than the many unreliable, uncontrolled studies available. Generally, the use of a placebo control has led to the elimination of numerous substances characterized by purely alleged efficacy, and to the identification of efficacious compounds or acceptable therapeutic trends. In peptic ulcer, controlled studies vs placebo have also contributed towards the acquisition and definition of useful pathophysiological, clinical and therapeutic notions.(ABSTRACT TRUNCATED AT 250 WORDS)