Salmeterol does not cause tolerance during long-term asthma therapy☆☆☆★★★ (original) (raw)

1996, Journal of Allergy and Clinical Immunology

Controversy regarding tolerance to [32-agonist asthma therapy has surfaced periodically over the past 20 years, and recently it has again become a focus of attention. Although there is evidence that tolerance develops to the nonpulmonary effects of [3z_agonist,1,2 there is still uncertainty among many clinicians who treat patients with asthma as to whether any clinically significant tolerance develops to the pulmonary effects of these drugs, particularly to the recently introduced long-acting 132-agonist salmeterol. This report, which represents results from the largest database of patients receiving salmeterol in clinical studies in the United States, supports the growing body of evidence that patients with asthma do not show any loss of bronchodilator effect after regular exposure to 132-agonist, 3-~ although some loss of the bronchoprotective effect has been reported in a few exercise-induced bronchospasm and methacholine challenge studies. 6, 9 METHODS Study design Four randomized, multicenter, double-blind, placebocontrolled, parallel-group studies were conducted in patients with reversible mild-to-moderate asthma (FEV, of 50% to 80% of predicted value after medication was withheld); two of the studies (n = 556), identically designed, evaluated salmeterol aerosol from a pressurized metered-dose inhaler (pMDI) 7, s; whereas the other two identically designed studies (n = 451) evaluated salmeterol powder, inhaled from a dry powder device (DPI)2 ~ All patients provided written informed consent, and the study protocols were approved by institutional review boards at each center. Patients were treated with one of the following for 12 weeks: salmeterol aerosol, 42 Ixg (actuated dose) twice