Psychotropic Drugs Linked to Increased Car Accident Risk

Antidepressants, benzodiazepines, and the sleeping pills known as Z-drugs are all associated with a significantly increased risk of car accidents, according to a new study.

Patients taking a range of antidepressants, sleeping pills, and anxiety medications are at increased risk of having a car accident, according to the results of a study published online on September 9, 2012, in the British Journal of Clinical Pharmacology. The study was based on data obtained from the National Health Insurance Research Database in Taiwan.

The researchers conducted a matched case-control study of 5183 subjects who had been in car accidents between 2000 and 2009 and 31,093 matched controls who had not been in a car accident. They analyzed the association between consumption of 4 classes of psychotropic drugs—antipsychotics, antidepressants (including SSRIs and tricyclics), benzodiazepines (long-acting, short-acting, hypnotics, and anxiolytics), and Z-drugs (sleeping pills such as zolpidem, zopiclone, and zaleplon)—and the risk of getting in a car accident within a day, a week, or a month of being prescribed the medication in question.

Their results showed that there was a significantly increased risk of having a car accident for those who had taken antidepressants for a month (adjusted odds ratio (AOR) of 1.73), for those who had taken antidepressants for a week (AOR of 1.56), and for those who had taken antidepressants for a day (AOR of 1.70). For those who had taken benzodiazepines for a month, a week, and a day, the AORs of having a car accident were, respectively, 1.56, 1.64, and 1.62. For those who had taken Z-drugs for a month, a week, and a day, the AORs of having an accident were, respectively, 1.42, 1.37, and 1.34. In addition, the results showed a dose effect, with the risk of getting in a car accident rising with increased doses of antidepressants, benzodiazepines, and Z-drugs. The results, however, indicated no increased risk of car accident associated with taking antipsychotics.

The researchers note that their study has the advantage of a large sample size and inclusion of multiple types of psychotropic drugs. They also note several potential shortcomings of their study: Their data did not include minor accidents for which participants did not visit medical facilities or accidents that resulted in death; their data only covers the dispensation of psychotropic drugs, not actual taking of them; and some risk factors may not have been taken into account, such as recent relocation, high job stress, driver’s license status, and use of alcohol or illicit drugs.

Nonetheless, the researchers argue that their results indicate that taking antidepressants, benzodiazepines, or Z-drugs significantly increases the risk of getting in car accidents and that patients taking these medications should be made aware of this risk and receive appropriate counseling from their health care providers.