Anticholinergic versus beta 2-adrenergic therapy in allergic airways obstruction: double-blind trials on bronchodilator effect and antiallergic protection of oxitropium bromide and fenoterol.

Two double-blind studies were performed in allergic subjects with bronchial asthma to evaluate the bronchodilator effect and antiallergic protection of oxitropium bromide (OTB), a new antiallergic drug. Study 1, bronchodilator trial: 2 puffs of OTB or provocation tests in 12 subjects each. The bronchodilator effect of FEN was significantly better (between 0 and 30 min after drug administration). At the same time there was an improvement of PaO2 after FEN (before: 62.4 Torr; after: 70.1 Torr), but not after OTB. Study 2, antiallergic protection: OTB or FEN were administered 30 min before bronchial allergen provocation tests in 12 subjects each, complemented by open DSCG controls. All 3 drugs provided significant protection compared with nonmedicated control tests, but only inhibition of FEN was complete. In conclusion, beta 2-adrenergic drugs seem to be superior to anticholinergic drugs in allergic asthma, not only as bronchodilators, but also as prophylactic agents.