Abstract
The mechanism of action of ketotifen in the prevention of bronchial asthma is discussed, the pathogenesis of the disease itself being taken as a starting point. The following biological effects of ketotifen may be relevant to its therapeutic activity: the inhibition of release of myotonic mediators, leukotrienes in particular, the inhibition of slow reactin ubstances-induced bronchoconstriction in vivo, calcium antagonistic properties, and the prevention or reversal of decreased β-adrenoceptor sensitivity. In asthmatic patients the prevention of bronchospasm due to mediator release and a progressive reduction of