Inhaled prazosin in asthma.
Prazosin, a potent and selective alpha-adrenergic antagonist, was given by inhalation to nine asthmatic subjects aged 25-48 years (six with positive skin tests). Prazosin 0.5 mg, salbutamol 1 mg, or placebo were given by nebuliser in randomised double-blind fashion on separate days. Although all subjects showed a significant increase in FEV1, vital capacity, and maximum expiratory flow at 70% of total lung capacity after salbutamol, there was no significant difference between prazosin and placebo. This suggests that alpha-adrenergic receptors are not important in the control of bronchial tone in asthma. The weak bronchodilatation ascribed to alpha-antagonists in previous studies could be explained by other pharmacological actions of the drugs used.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000328:Adult; D000420:Albuterol / Q000494:pharmacology; D001249:Asthma / Q000503:physiopathology*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011224:Prazosin / Q000008:administration & dosage / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D011897:Random Allocation; D012119:Respiration / Q000187:drug effects; D012129:Respiratory Function Tests
D000317:Adrenergic alpha-Antagonists; D011799:Quinazolines; D000420:Albuterol; D011224:Prazosin