INTRODUCTION: Although there have been experimental studies concerning driving and drugs, studies on the risk of antihistamines are not numerous. This is the first population-based epidemiological study concerning the association of sedating/non-sedating antihistamines and fatal traffic accidents.
METHODS: Car drivers (n = 428) who died in accidents before reaching hospital and controls (n = 688) matched for accident area and driving season were studied for antihistamines in blood. At the time of the fatal road traffic accident, 6 drivers had a detectable amount of sedating antihistamines in blood, while the corresponding number for controls was 4; non-sedating antihistamines in blood were detected in 12 accident cases and 28 controls. The fatal accidents occurred between 1998-2002 and the information on the controls was collected between 2000-2002 in Finland.
RESULTS: Regarding fatal traffic accident causality, the non-sedating antihistamines proved to have a protective effect after adjusting for age and gender (RR = 0.40 0.20 to 0.82 95% CI, p = 0.01). The risk of fatal traffic accident of those driving under the influence of sedating antihistamines was 1.61 (0.38 to 6.77, p = 0.51) times the risk of those without medication.
DISCUSSION: This preliminary study supports the protective effect of second generation antihistamines with respect to fatal traffic accidents. Due to the small sample size the results not conclusive.