GHB use among seriously injured car drivers who were admitted to hospital. The drug GHB (gamma-hydroxybutyric acid) is mainly used for recreation as a club drug. Several studies among car drivers whom the police suspected to have driven under the influence indicate that GHB use can lead to unsafe driving. These negative effects on driving were reason to include GHB in the law proposal for legal limits for drugs in traffic that was offered to the Council of State of the Netherlands in April 2011. The legal limit that was proposed for GHB is 10 nanograms per millilitre blood or serum (ng/ml). To our knowledge no experimental or epidemiological studies have been carried out into the precise effect of GHB use on road safety. As mentioned, there have been studies that were based on police reports or blood analyses of car driver who were already suspected of having used drugs. There is no data, however, on the precise effects of GHB on driving skills and the prevalence and risks of GHB in traffic. In this exploratory study the GHB concentrations were determined in 180 serum samples of seriously injured car drivers who had been admitted to three hospitals in the cities Enschede, Tilburg and Nijmegen during the period 2007-2009. Within the EU project DRUID (Driving Under the Influence of Drugs, Alcohol and Medicines) these serum samples had previously been tested for alcohol and 22 other psychoactive substances. Five of the 180 seriously injured car drivers tested positive for GHB. Their serum values ranged from 42 ng/ml to 424 ng/ml. In comparison with the use of other drugs, the prevalence of GHB among the seriously injured car drivers is relatively high with 5 in 180 (2.8%). This seems to indicate that GHB use does indeed have a negative effect on road safety. However, to which extent GHB also increases the risk of sustaining serious injury in a road crash can only be determined if data on the prevalence of GHB in traffic is also available. Therefore, it is to be recommended to include GHB in the list of substances to be analysed for in future studies into the use of drugs in traffic. Relatively often, the GHB positive car drivers who are admitted to hospital with serious road injury seem to be young males who relatively often do not use the seat belt and who are relatively often involved in single vehicle crashes. As the number of seriously injured GHB positive car drivers is small, these results must be interpreted with some caution. However they seem to be similar to the results in Norwegian, Swedish and American research findings.
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