[Ketotifen in the prophylaxis of infantile asthma. Controlled clinical trials].

The heterogeneity in the aetiology and the precipitating factors, as well as the pathology of asthma makes the response to the conventional treatment also variable. Ketotifen is a derivative of the cyclohepatotifen which has shown to have an antianaphylactic effect which inhibits chemical mediator release in mast cells and basophils. This effect is similar to that of the methylxanthines inhibiting phosphodiesterase propitiating the increase of CAMP and favouring bronchodilatation. It also exerts a blocking action on the H receptors of histamine and possesses a calcium antagonist effect in the depolarized smooth muscle; for this reason it is probable that ketotifen does not have a direct effect on the contraction of smooth fibres provoked by diverse stimuli. The present work is a prospective study with placebo group and double blind method to evaluate the effectivity and tolerance of ketotifen as a prophylaxis for extrinsic bronchial asthma in 60 children. This is to observe if there exists or not a reduction in the frequency, intensity and duration of signs and symptoms. Among the most interesting conclusions observed are the following: The general characteristics of both the ketotifen group as well as the placebo group did not show any significative statistical differences which were susceptible of comparison among them. The ketotifen proved itself as very efficient, obtaining a reduction which was highly significative of the asthmatic symptomatology (p less than 0.001). In the placebo group some highlights were obtained which can be attributed to the fact that both groups received desensitizing immunotherapy to diverse allergens. Nevertheless, in general terms, the symptomatology did not diminish in this group in a significative way.(ABSTRACT TRUNCATED AT 250 WORDS)