Ketotifen in the oral prophylaxis of bronchial asthma: a review

The experimental data providing the rationale for the use of ketotifen as a prophylactic drug in asthma (inhibition of release of the mediators of anaphylaxis, particularly SRS-A, prevention of the bronchospasm induced by SRS-A in vivo, calcium antagonist effect) are briefly discussed, and the results of experimental and therapeutic trials carried out over 6 years in a number of countries in several thousand patients are reviewed. Some important features of oral asthma prophylaxis with ketotifen are underlined, namely the effect of ketotifen on the characteristic bronchial hyperreactivity of asthma, the types of asthma which respond best to ketotifen treatment, the effect of ketotifen in reducing the concomitant use of corticosteroids and bronchodilators, a comparison of ketotifen with specific antihistamines, theophylline derivatives and sodium cromoglycate, and the side-effects and long-term safety of ketotifen.