[Ipratropium Bromide, an Anticholinergic Bronchodilator/Behavior of airways resistance in patients with reversible respiratory obstruction following inhalation of various doses of ipratropium bromide].

A dose- and time-response study using different doses of an inhaled derivative of atropine, (8r)-3alpha-hydroxy-8-isopropyl-1 aH, 5aH-tropaniumbromide-(+/-)-tropate (Sch 1000, ipratropium bromide, Atrovent) was performed in 12 patients with reversible chronic obstructuve airways disease. The drug was shown to be an effective bronchodilator with the typical action of reducing airways resistance with 2 puffs (0.02 mg per puff). Increasing the dose to 4 and 8 puffs did not produce any relevant difference in time response. The onset of action was rapid and reached a maximum between 30 and 60 min after inhalation. The duration of bronchodilation was maintained during the observation period of 3 h. 30 min after inhalation the results corresponded to those following the inhalation of 2 puffs of orciprenaline (0.75 mg per puff). Isolated side-effects were independent of the dosage.