THE EFFECTS OF SINGLE ACUTE THERAPEUTIC DOSES OF PENTOBARBITONE, ALONE AND IN COMBINATION WITH ALCOHOL, ON HUMAN PERFORMANCE IN DRIVING- RELATED TESTS: EXPLORATION OF THE RELATIONSHIPS BETWEEN PERFORMANCE DECREMENTS AND BLOOD CONCENTRATIONS OF PENTOBARBITONE AND ALCOHOL

A placebo-controlled study was carried out to examine the effects of pentobarbitone, alone and in combination with a "social" dose of alcohol, on human performance in tests which examine aspects of the driving task. The relationships between the nature and extent of psychomotor impairment and the concentrations of pentobarbitone and alcohol in the blood were also examined. Pentobarbitone alone caused impairment in groups which received the drug. When alcohol was given concomitantly with pentobarbitone, there was a greater and more sustained psychomotorimpairment than with the same dose of pentobarbitone taken alone. After pentobarbitone, most subjects reported reduced coordinative and cognitive capacity and increased sedation. They also reported a reduction in willingness to drive. Some subjects reported double vision and feelings of de- realisation. Many subjects reported rebound impairment after leaving the laboratory which lasted well into the evening.