Protective effect of tulobuterol on methacholine-induced bronchospasm in asthmatic children.

In a single-blind, placebo-controlled trial 19 asthmatic children aged 10-14 years were studied during a stable phase of the disease. All patients were tested with a methacholine inhalation test on two consecutive days, on the first day after oral administration of a placebo, and on the second day following an oral dose of tulobuterol HCl. The cumulative methacholine dose required to produce at least a 20% decrease in FEV1 was significantly higher after tulobuterol than after the placebo. It is concluded that tulobuterol HCl reduces methacholine-induced bronchospasm in children.