A placebo controlled investigation into the effects of paroxetine and mirtazapine on measures related to car driving performance.

OBJECTIVE

To assess the effects of paroxetine and mirtazapine on psychometric performance related to car driving, including an on-the-road test of BRT.

METHOD

In a 4-way, double blind randomised crossover study, 12 healthy volunteers received paroxetine 20mg mane, mirtazapine 15mg/30mg nocte (comparator), mirtazapine 15mg mane/15 mg b.i.d.(verum) and placebo over a 5 day period with a washout period of 7 days between treatments. Psychometric assessments included 'on-the-road' BRT (BRT), CFF (CFF), CRT (CRT) and subjective measures of sedation and sleep parameters.

RESULTS

Paroxetine had no significant effect on BRT compared with placebo. Although subjective ratings of sleep quality and sedation were impaired, there were significant improvements in both CFF and the recognition reaction component of CRT with paroxetine. Mirtazapine 15mg/30mg nocte impaired laboratory performance and some subjective tests. Mirtazapine 15mg mane/15mg b.i.d. improved sleep, but significantly impaired all other measures.

CONCLUSION

Paroxetine 20 mg/day has no psychomotor or behavioural toxicity and has no negative impact on BRT. Further research into the chronic and sub-chronic effects of mirtazapine is needed to establish the clinical significance of these results.