Table 1.

Summary of results from the driving and psychomotor tests on day 1 and day 8

	Mean ± SEM per treatment				Treatment effect
	CET	PLA	MEQ	DEX	F	d.f.	P	N
Day 1
Driving tests
SDLP (cm)	18.4 ± 0.8	19.2 ± 1.0	21.7 ± 1.1a	21.2 ± 1.3a	8.16	3,39	<0.001	15
Time to speed adaptation (s)	2.1 ± 0.3	1.9 ± 0.2	2.3 ± 0.3	2.0 ± 0.4	1.02	3,38	NS	14
Brake reaction time (ms)	537 ± 24	476 ± 19	528 ± 29	492 ± 26	2.36	3,38	NS	14
SD distance (m)	5.3 ± 0.7	5.2 ± 1.1	4.3 ± 0.7	4.0 ± 0.5	0.74	3,38	NS	15
Critical tracking task
Critical frequency (rad/s)	4.0 ± 0.2	3.9 ± 0.2	3.8 ± 0.2	3.9 ± 0.2	1.21	3,39	NS	15
Divided attention task
Tracking error (mm)	20.4 ± 1.4	21.2 ± 1.5	21.1 ± 1.2	22.9 ± 1.4	2.83	3,39	0.051	15
Reaction time (ms)	1807 ± 69	1747 ± 64	1799 ± 54	1809 ± 70	0.76	3,39	NS	15
Day 8
Driving tests
SDLP (cm)	19.6 ± 1.0	19.9 ± 1.0	21.0 ± 1.2	19.9 ± 1.0	0.99	3,39	NS	15
Time to speed adaptation (s)	2.0 ± 0.2	2.2 ± 0.2	2.2 ± 0.3	2.0 ± 0.2	0.80	3,38	NS	14
Brake reaction time (ms)	510 ± 27	506 ± 23	521 ± 33	484 ± 14	0.60	3,38	NS	14
SD distance (m)	5.1 ± 0.8	5.5 ± 1.2	5.0 ± 0.7	4.5 ± 0.8	0.41	3,36	NS	12
Critical tracking task
Critical frequency (rad/s)	3.9 ± 0.2	4.0 ± 0.2	4.0 ± 0.2	4.0 ± 0.2	0.32	3,39	NS	15
Divided attention task
Tracking error (mm)	20.4 ± 1.3	20.0 ± 1.3	20.6 ± 1.3	20.9 ± 1.6	0.39	3,39	NS	15
Reaction time (ms)	1832 ± 69	1787 ± 98	1692 ± 59	1721 ± 77	1.53	3,39	NS	15

Treatments are placebo (PLA), mequitazine 10 mg q.a.m. (MEQ), cetirizine 10 mg q.a.m. (CET) and dexchlorpheniramine 6 mg Repetab b.i.d. (DEX). Significant drug–placebo differences are indicated by SDLP, standard deviation of lateral position.

^aP < 0.017. NS, Not significant; d.f., degrees of freedom.