Abstract

Subacute effects of C, T, S, or B, alone or in combination with A, were tested against P in two double-blind crossover trials with 37 healthy students. The drugs were given in capsules t.i.d. for 2 weeks each and the psychomotor performance (choice reaction, coordination, attention) was measured on the 7th and 14th days of treatment. At each session the subjects swallowed a capsule together with 0.5 g/kg of A or P drink, and the measurements were done, 30, 90, and 150 min thereafter. T alone did not differ from placebo in the doses used (10 mg t.i.d. for 7 days and 20 mg t.i.d. for the next 7 days). After C (dosing as above) and S (50 mg t.i.d.) both reactive and coordinative skills were slightly impaired. B (6 mg t.i.d.) clearly impaired both reactive skills and attention. T + A had no major combined effect on skills while C interacted with A resulting in impaired reactive and coordinative skills. After C + A the subjects were unable of compensating their coordination mistakes by slow driving. The interaction of S with A was mild, whereas B + A strongly impaired coordination and divided attention. No alterations were recorded in flicker fusion after any treatment.