Combining tiotropium and salmeterol in COPD: Effects on airflow obstruction and symptoms

SummaryBackgroundClinical information on 24-h spirometric efficacy of combining tiotropium and salmeterol compared to single-agent therapy is lacking in patients with COPD.MethodsA randomized, double-blind, four-way crossover study of 6-week treatment periods comparing combination therapy of tiotropium 18 μg plus qd or bid salmeterol 50 μg versus single-agent therapy. Serial 24-h spirometry (FEV1, FVC), effects on dyspnea (TDI focal score) and rescue salbutamol use were evaluated in 95 patients.ResultsTiotropium plus qd salmeterol was superior to tiotropium or salmeterol alone in average FEV1 (0–24 h) by 72 mL and 97 mL (p < 0.0001), respectively. Compared to this qd regimen, combination therapy including bid salmeterol provided comparable daytime (0–12 h: 12 mL, p = 0.38) bronchodilator effects, but significantly more bronchodilation during the night-time (12–24 h: 73 mL, p < 0.0001). Clinically relevant improvements in TDI focal score were achieved with bronchodilator combinations including salmeterol qd or bid (2.56 and 2.71; p < 0.005 versus components). Symptom benefit of combination therapies was also reflected in less need for reliever medication. All treatments were well tolerated.ConclusionCompared to single-agent therapy, combination therapy of tiotropium plus salmeterol in COPD provided clinically meaningful improvements in airflow obstruction and dyspnea as well as a reduction in reliever medication.