Λεξικό .. Bronchodilators

Agents that cause expansion of the lumina of the air passages of the lungs and other obstructive airways diseases. They are drugs used in asthma and other obstructive airways diseases. They include: Methylxanthines (Theophylline, enprofylline, etc.), beta-receptor agonists or β2 agonists or β2-adrenergic bronchodilators, and anticholinergics (e.g. Ipratropium bromide).The most striking development in bronchodilator therapy for asthma during the last years are the long-acting sympathomimetics formoterol or salmeterol. Both inhaled sympathomimetics cause a bronchodilation that lacts for at least twelve hours. Formoterol has been shown to cause a significant bronchodilation after single doses of 6 mcg and above. 48 mcg and higher doses are associated with significant side effects especially tremor and palpitations.

Salmeterol has significant bronchodilating activity at single doses of 12.5 mcg and above. 100 mcg and higher doses cause an increased incidence of tremor and palpitations. Formoterol has a very rapid onset of bronchodilating activity, comparable to salbutamol. The onset of action of salmeterol is slightly slower. Both formoterol and salmeterol protect against various non allergenic stimuli and the duration of the protective activity extends beyond twelve hours. Both longacting sympathomimetics equally protect against the early and the late asthmatic reaction following allergen challenge.

Chronic treatment with formoterol and salmeterol results in a significant decrease of the daytime and nighttime asthma symptoms, an increase in both morning and evening peak flow and a decrease in the use of rescue bronchodilators. No signs of tachyphylaxis are observed even after prolonged treatment. The clinical importance of the potential anti-inflammatory properties of these long-acting sympathomimetics remains to be established.ReferencesPauwels, R.: New developments in bronchodilators. Symposium 8. New-Antiallergic and Anti-Asthma Drugs. In the EAACI Congress, Zurich, May 28th, 1991.