ABSTRACT
Xamoterol, a partial agonist of beta 1-adrenoceptors, was tested as a cardiotonic drug in 10 patients with moderate chronic heart failure. The trial was double-blind drug versus placebo for 3 months and open for one year. At 3 months the patients were clinically improved with downgrading by one NYHA class, and there was a significant increase in response to a 36-second exercise, as compared with the placebo group. Haemodynamic index, a 14 per cent fall in pulmonary wedge pressure and a 7 per cent increase in left ventricular stroke work as compared with the placebo group. This clinical and haemodynamic improvement was paralleled by a reduction of the double product on exercise. In long term use, xamoterol did not seem to induce tachyphylaxis, and few side-effects were recorded during this trial.
