CARDIOVASCULAR EFFECTS OF NEBULIZED FENOTEROL IN HEALTHY-VOLUNTEERS

Fenoterol increases the heart rate and cardiac output significantly co mpared to other selective beta(2)-agonists. The drug was marketed at a higher equivalent dose than other beta-agonists, but is currently ava ilable in South Africa as 100 mu g per puff in metered dose inhalers. The aim of this study was to assess the cardiovascular effects of the lower dose of fenoterol. Ten healthy volunteers inhaled either 100 mu g or 200 mu g fenoterol or placebo from a Nebulisation Dosimeter, afte r baseline recordings of heart rate, blood pressure and systolic time intervals were registered. These were repeated 15 and 30 min after inh alations. The 200 mu g dose of fenoterol decreased QS(2)I (total elect romechanical systole corrected for heart rate) significantly at 15 min , with no further changes at 30 min, compared to placebo. There were n o significant changes in heart rate, systolic or diastolic blood press ure with any of the treatments. We conclude that the 100 mu g dose of fenoterol causes minimal cardiovascular changes.