A comparison of the effects of flosequinan, a new vasodilator, and propranolol on sub‐maximal exercise in healthy volunteers.

Abstract

1 The effects of steady state flosequinan, a new vasodilator, and propranolol, on glucose mobilisation, lipolysis and plasma potassium concentration during sub-maximal exercise testing were investigated in a double-blind, randomised, three-way crossover study in 12 healthy volunteers. 2 Plasma glucose, potassium and free fatty acid concentration during and after exercise on flosequinan were similar to those on placebo. Exercise heart rates were 7% (+9.2 beats min-) higher on flosequinan compared with placebo (P < 0.05). During exercise on propranolol plasma glucose concentrations were comparable with those on placebo but plasma potassium concentrations were higher (mean increase 0.26 mmol 1-1, P < 0.01) whereas free fatty acid concentrations were lower (mean decrease 0.10 mmol 1-1, P < 0.01). As expected the heart rate on exercise was 25% less (-35 beats min-') on propranolol (P < 0.05). 3 These data suggest that, in contrast to propranolol, flosequinan does not adversely affect the mobilisation of the two major sources of energy during sub-maximal exercise.