Double-blind cross-over comparison of clenbuterol and salbutamol tablets in asthmatic out-patients.

A double-blind cross-over comparison of a new beta2-sympathomimetic bronchodilator, clenbuterol, with salbutamol and placebo has been made during a 24 day period of out-patient treatment of 19 adults with moderately severe asthma. Oral clenbuterol (10 mug 3 times a day) and salbutamol (4 mg 3 times a day) were equally and significantly (p less than 0.001) more effective than placebo, when daily records of peak expiratory flow or use of isoprenaline inhalations were the criteria of activity. Daily records of symptoms according to a questionnaire also suggested relief of the subjective effects of asthma during treatment with both active drugs (p less than 0.01).