Twenty healthy subjects took amitriptyline, doxepin, and placebo for 2 wk each in a double-blind crossover trial, and another 20 subjects similarly took nortriptyline, chlorimipramine, and placebo. The antidepressants were given three times daily in doses generally used for neurotic patients. The presence of antidepressants in tissues was checked with the tyramine pressor test. On the seventh and fourteenth days of each period, psychomotor skills (choice reaction, coordination, and attention) were measured after the administration of drugs in combination with an alcoholic or placebo drink. Dose-response graphs for the tyramine pressor effect were shifted to the right during the antidepressant treatment, indicating a blockade of the membrane pump in peripheral sympathetic terminals. This antityramine effect of antidepressants did not correlate with their psychomotor effects. No drug alone importantly impaired psychomotor skills. Amitriptyline in combination with alcohol increased cumulative choice reaction times, and doxepin in combination with alcohol increased both cumulative choice reaction times and inaccuracy of reactions. Coordination was impaired after both of these combinations on the seventh day. It seems as if doxepin and amitriptyline but not nortiriptyline or chlorimipramine, in combination with 0.5 gm/kg of alcohol, may be especially dangerous in driving.
A computerized device for simultaneous measurement of coordinative and reactive skills related to driving was developed and tested in two consecutive trials of psychoactive agents in healthy volunteers. The test system comprises a vehicle, a driving computer (Sinclair QL), and the programming and measurement computer (IBM-PC). The computerized driving programme projects to the colour--TV screen a winding road, and the driver has to keep the car on the road by turning the steering wheel. The driving proceedes at a fixed, fairly rapid rate for 5 min., and the numbers of tracking errors (deviations from the road) as well as the tracking percentage (relative length of the track driven off the road) were computed separately for both halves of the track. During the latter half of the track 60 visual or/and sound stimuli were given in random order, and the driver had to respond or not respond to them by pressing a button or by pushing a foot pedal. The number of reaction errors and the cumulative reaction time were recorded. The programme also provides a histogramme that relates the number of deviations from the road to their duration, enabling a visual judgement of the severity of errors. Matched versions (mirror image, reverse direction) of tracks of varying severity were offered to reduce learning effect during the trial. When testing the device in two placebo-controlled double-blind and cross-over trials, a considerable practice effect on tracking and reaction strategies took place, but after proper training the baselines remained reasonably stable.(ABSTRACT TRUNCATED AT 250 WORDS)
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.