An acute bronchodilator test with tiotropium or salmeterol does not allow a subdivision of patients according to responses.
BACKGROUND
The possibility that individual chronic obstructive pulmonary disease (COPD) patients respond better to either tiotropium or salmeterol has been suggested and an acute bronchodilator test might help to guide the choice of therapy.


OBJECTIVE
We explored the responses to tiotropium and salmeterol within the first 3 h using the recommended dosages (18 microg for tiotropium and 50 microg for salmeterol) in order to verify whether there are differences in the short-term bronchodilator effects between these two long-acting bronchodilators in patients with stable COPD. Moreover, we investigated whether these differences could discriminate between the two agents.


METHODS
Forty consecutive patients with COPD, but in a stable phase of the disease, participated in this double-blind, double-dummy, randomized crossover study. The study involved a screening visit and 2 study days separated by at least 1 week. For determination of the onset of action, we measured FEV1 at 10, 20, 30, 60 and 90 min, and again 2 and 3 h after inhalation of single study drug.


RESULTS
At all time points, both tiotropium and salmeterol caused significant (p< 0.001) changes from baseline. A mean increase of 12% above baseline was reached 66 min (95% CI: 45-87) after tiotropium and 59 min (95% CI: 41-77) after salmeterol. Nine patients after tiotropium and 5 patients after salmeterol did not have this type of improvement. A mean increase of 200 ml above baseline was reached 76 min (95% CI: 52-101) after tiotropium and 76 min (95% CI: 52-100) after salmeterol. Eighteen patients after tiotropium and 15 patients after salmeterol did not have this improvement. Twenty-one patients after tiotropium and 24 patients after salmeterol reached an improvement that was at the same time 12% and 200 ml greater than baseline.


CONCLUSIONS
These data clearly show that the bronchodilator effects of tiotropium and salmeterol within the first hours after their acute administration are similar in patients with stable COPD when they are evaluated as mean changes from baseline in FEV1. Therefore, they question the direct therapeutic relevance of a subdivision of patients according to bronchodilator responses to tiotropium or salmeterol.
Matera
M G
MG
Unit of Pharmacology, Department of Experimental Medicine, Second University of Naples, Naples, Italy.
Sanduzzi
A
A
Ponticiello
A
A
Vatrella
A
A
Salzillo
A
A
Cazzola
M
M
D000280:Administration, Inhalation; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D036501:Metered Dose Inhalers; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D000068299:Salmeterol Xinafoate; D012602:Scopolamine Derivatives / Q000008:administration & dosage / Q000627:therapeutic use*; D000069447:Tiotropium Bromide; D016896:Treatment Outcome
D001993:Bronchodilator Agents; D012602:Scopolamine Derivatives; D000068299:Salmeterol Xinafoate; D000420:Albuterol; D000069447:Tiotropium Bromide