In vitro ketotifen protection in bronchial hyperreactivity.

There are drugs, such as ketotifen, that inhibit bronchospasm through different mechanisms. In this study, we looked at the changes in the number of sanguineous cells that ketotifen produces, especially in basophil cells, that could explain its prophylactic effects in bronchial hyperreactivity disclosed by exercise, as well as its relation to the variations in basal and total histamine in blood. 22 patients were selected, with a diagnosis of extrinsic bronchial asthma with sensitization against Dermatophagoides, and were compared to a control group. They all underwent an exercise test. Blood samples were taken before and after exercise in order to measure the number of leukocytes and the changes in basal and total histamine. We found that the number of basophils does not increase after exercise in untreated patients, while it does in the control group and in treated patients. This implies that ketotifen stabilizes the basophil cells, hindering their degranulation and the subsequent liberation of mediators that would produce bronchospasm after exercise.