Prednisolone hastens recovery from histamine-induced bronchospasm in asthmatics

Short-term treatment with oral steroids is very effective in control ling symptoms and improving lung function in asthma but has not been shown unequivocally to reduce bronchial hyperresponsiveness. Recently it has been shown to increase the activities of sodium-potassium and calcium adenosine triphosphatases, enzymes that regulate intracellular calcium levels. This action may be expected to promote recovery of cells from an excitatory stimulus. The present study was carried out to determine how prednisolone modulates airway response to histamine, including recovery from induced bronchospasm in asthmatics. Spirometry and measurement of bronchial responsiveness (forced expiratory volume in 1 sec [FEV1] and concentration of histamine causing a 20% reduction FEV1 [PD20 FEV1]) to inhaled histamine were carried out in 10 clinically stable asthmatics. Subsequently, all of the patients were prescribed oral prednisolone, 0.6-0.75 mg/kg body weight for 1 week. At the end of 1 week, spirometry was repeated and bronchial reactivity was measured again. Comparison of PD20 FEV1 values before and after treatment (geometric means 0.66 and 0.81 mg/mL, respectively) for the whole group did not show any significant change. The mean +/- SD time for 95% recovery from histamine-induced bronchospasm was 33.00 +/- 19.47 min before treatment and decreased significantly to 18.00 +/- 7.88 min after treatment. It was concluded that short-term benefits from oral prednisolone do not result from changes in bronchial responsiveness. These benefits may be related to effects on mechanisms that lead to recovery from an excitatory stimulus.