Twenty healthy subjects were used in a double blind study to test the two beta receptor blocking drugs propranolol and pindolol with respect to their effect on drivers and driver behavior. The driving tests were conducted on a test ground. In addition to several psychophysiological parameters and psychomental performance tasks, driver behavior was studied by means of special auxiliary driving tasks.

Apart from the effects on the heart and circulation system, predicted on the basis of the pharmacodynamics of beta blockers, a clear change in psychophysiological reactions was established. The effect of beta blockers on psychomotoric coordination and reactivity is negative. These results, together with the sedative side effects reported by many subjects, are interpreted as a general reduction of activation due to the ingestion of beta blockers.