Tolerance to inhaled Duovent. A long-term study.
Fenoterol with ipratropium bromide (Duovent) is a recently used combination between an anticholinergic and a beta-adrenergic drug useful in obtaining a more effective bronchodilatation and/or reducing the single drug doses. It has been suggested that, as in the case of beta-agonists, its clinical efficacy may be limited by the development of tolerance. We studied the effects of inhaled Duovent in 15 asthmatic patients for 3 months, using a rigidly controlled protocol. Appropriate serial physiological measurements were made at regular intervals during the 90-day study. In all instances the day-one bronchodilator response was significant, prompt and sustained: at 1, 4, 8 and 12 weeks the response was statistically the same as on day 1. It is concluded that, when the important variables are properly controlled, no evidence of tolerance to long-term therapy with Duovent is demonstrable.
D000328:Adult; D001286:Atropine Derivatives / Q000008:administration & dosage*; D004338:Drug Combinations / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D004361:Drug Tolerance; D005280:Fenoterol / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D005541:Forced Expiratory Volume; D006801:Humans; D009241:Ipratropium / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D008137:Longitudinal Studies; D008173:Lung Diseases, Obstructive / Q000188:drug therapy / Q000503:physiopathology; D009330:Nebulizers and Vaporizers
D001286:Atropine Derivatives; D004338:Drug Combinations; C030809:fenoterol, ipratropium drug combination; D005280:Fenoterol; D009241:Ipratropium