agonist: comparison with salbutamol in adult asthmatic patients

Salmeterol is a new inhaled 2 adrenoceptor agonist, which has been shown in animal experiments to produce a more prolonged bronchodilator effect than currently available f2 adrenoceptor agonists. It was studied in eight adult asthmatic patients. Each patient received on separate test days salbutamol 200 pg and salmeterol 50, 100, and 200 pg according to a randomised, double blind, crossover design. FEV1, peak expiratory flow (PEF), heart rate, blood pressure, and tremor were recorded in the clinic for six hours after drug inhalation; PEF was recorded for a further six hours at home. All three doses ofsalmeterol produced peak increases in FEV1 (mean 0*5-048 1) and PEF (71-100 I/min) similar to those produced by salbutamol 200 yg (051 and 74 1/min). After salbutamol FEVy and PEF had returned to baseline within six hours, but after all three doses of salmeterol more than halfof the maximum bronchodilator effect remained after 12 hours. The effects ofsalbutamol and the two lower doses ofsalmeterol (50 and 100 ug) on cardiovascular measurements and on tremor were similar, whereas after salmeterol 200 pg there was a small decrease in diastolic blood pressure and an increase in heart rate and tremor. Thus inhaled salmeterol has a long acting bronchodilator action in asthmatic patients. This effect may be of value in the treatment of asthma, particularly in patients with nocturnal symptoms. Introduction Salmeterol Inhaled f2 adrenoceptor agonists have become established as first line treatment for the management of acute asthma because oftheir excellent bronchodilator effects, wide therapeutic range, and low level of side effects." The major disadvantage of currently available inhaled 2 adrenoceptor agonists is their short duration of action; none of the currently available inhaled f agonists has an effect lasting for more than six hours.56 Consequently, oral bronchodilator drugs may need to be added to other treatment for patients with early morning dyspnoea or wheeze. The availability of a longer acting inhaled 2 adrenoceptor agonist would therefore appear to be an important therapeutic advance. Salmeterol hydroxynaphthoate is a 2 adrenoceptor agonist that has been shown to produce long acting bronchodilatation in both in vitro and in vivo animal Address for reprint requests: Dr Anders Ullman, Department of Clinical Pharmacology, Sahlgrenska University Hospital, S413 45 Gothenburg, Sweden. Accepted 20 May 1988 CH (OH)CH2NH (CH2)60(CH2)4Ph