ABSTRACT Background Traffic safety is compromised whenever people participate in traffic under the influence of psychoactive substances, i.e. alcohol and prescription-and non-prescription drugs 1 . Crash rates have been shown to be higher...
moreABSTRACT Background Traffic safety is compromised whenever people participate in traffic under the influence of psychoactive substances, i.e. alcohol and prescription-and non-prescription drugs 1 . Crash rates have been shown to be higher in drivers under the influence of alcohol and prescription-and non-prescription drugs 2 . The incidence of drivers under the influence of psychoactive drugs in actual traffic is considerable (5-17%) and increasing in most western countries 3 . Epidemiological data of high quality on the use of illicit substances such as cannabis, MDMA, amphetamines and other psychostimulants in traffic are sparse, but seem to point out that driving home after a party under the influence of so-called 'party drugs' or 'dance drugs' is increasing. When interviewed at the location of a dance party in the Netherlands, 6% of those who indicated they would be driving home afterwards had used MDMA and was still under the influence 4 . Most likely this is an underestimation and usually this would occur during late night hours when accident statistics are already elevated. Several fatal and non-fatal injurious road-accidents have been reported in which MDMA was found in the plasma of drivers, or those held responsible for the crashes 5 . Eleven cases of crashes by 5 drivers 4-6 hours after MDMA use, i.e. when leaving dance-parties, have been described in somewhat more detail. Vehicle operation after MDMA use was manifested as bizarre behaviour, inadequate attention, alienation, speeding and increased risk taking 6 . These findings clearly stress the need to further investigate the putative impairing influence of illicit drugs on driving performance or driving-related psychomotor performance in an experimental manner 7 . Another issue, related to the above, is polydrug use in traffic. The incidence of concomitant use of other recreational drugs such as cannabis and alcohol among XTC users has been shown to be as high as 80-90% 8 . It has become increasingly clear that the effects of many drugs, when taken concurrently are not necessarily predictable on the basis of knowledge of their effects when given alone. When MDMA users take several drugs concurrently, they face the problem of knowing whether a specific combination of drugs causes an interaction. A drug interaction refers to the possibility that one drug may alter the intensity of pharmacological effects of another drug given concurrently. The net results may be enhanced or diminished effects of one or both drugs or the appearance of a new effect that has not been observed with either drug alone.
