Ketotifen: current views on its mechanism of action and their therapeutic implications.

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 reacting substances-induced bronchoconstriction in vivo, calcium antagonistic properties, and the prevention or reversal of decreased beta-adrenoceptor sensitivity. In asthmatic patients the prevention of bronchospasm due to mediator release and a progressive reduction of bronchial hyperreactivity are the major consequences of these properties.