The need to manage the key symptoms of chronic obstructive pulmonary disease (COPD) (breathlessness, cough and sputum) is an important treatment objective. Viozan (sibenadet HCl, AR-C68397AA) is a novel dual D2 dopamine receptor, beta2-adrenoceptor agonist, which combines conventional bronchodilatory activity with the sensory nerve modulation afforded by dopamine agonism. The efficacy of this agent in relieving patient symptoms has been determined in a series of large-scale clinical studies; the results of a 3-month, placebo-controlled multi-centre study are reported. Effect on patient symptoms was determined using a novel patient-reported assessment instrument, the Breathlessness, Cough and Sputum Scale (BCSS). Patients with smoking-related COPD were required to complete a 2-week baseline period before being randomized to one of three treatment groups; sibenadet (500 microg three times daily) plus placebo (twice daily); salmeterol (50 microg twice daily) plus placebo (three times daily); placebo (twice daily) plus a second placebo (three times daily). All treatments were delivered via pressurized metered dose inhaler (pMDI) for 12 weeks. From enrolment, patients were required to complete daily diary cards to record symptoms of breathlessness, cough and sputum, medication use and adverse events. The primary outcome measure was the difference between the mean BCSS total score measured over the baseline period and the mean BCSS total score in the final 4 weeks of the treatment period. Secondary measures included assessment of lung function, rescue medication use, exacerbations, health-related quality of life, opinion of efficacy and safety. Although an initial reduction in BCSS total score (indicating symptom improvement) was seen with sibenadet therapy, this effect was not maintained for the study duration. Salmeterol therapy, however, resulted in a sustained reduction in BCSS total score. No notable benefit over placebo was seen in lung function, exacerbations or health-related quality of life with either active treatment. While the results of this study failed to demonstrate sustained efficacy with sibenadet therapy, they do indicate the value of symptom assessment in the clinical evaluation of new drugs for the treatment of COPD.