The effects of ceasing opioid, benzodiazepine, or Z-hypnotic drug use on measures of driving performance and postural balance.

Benzodiazepines, Z-hypnotics, and opioids are classes of psychoactive
medications that have been linked to increased accident risk, i.e. traffic
accidents and falling, based on epidemiological findings. Furthermore,
experimental data demonstrates the acutely intoxicating effects of these
medications on measures of driving performance and postural balance. Continued
use of these medications is often advised against due to tolerance development,
the risk of becoming dependent, or the development of long-term side effects.
Hence, continued use can be an unnecessary risk to the patient. The Jessa
Hospital in Hasselt, Belgium, has launched an initiative to identify patients
using these and other drugs inappropriately or unnecessarily, and consequently
attempts to withdraw these patients from these drugs. Some evidence supports
the effectiveness of withdrawal interventions with respect to falling risk.
However, when it comes to driving performance little *if any- evidence exists.

The aim of this study is primarily to investigate the effects of a withdrawal
intervention on measures of driving performance in a clinical population that
uses benzodiazepines, Z-hypnotics, or opioid analgesics chronically. As a
secondary objective, this study also aims to replicate previous findings that
demonstrate that fall risk decreases after cessation of psychoactive
medications by observing the effects of cessation on measures of postural
balance.

The proposed study is a 3 (groups) by 2 (repeated measures) mixed design.
Participants who use a medication of interest chronically will be invited to
have their medication schedule examined and revised if applicable. Patients who
are advised to cease the use of a medication of interest will be invited for a
training day, a pre-cessation, and a post-cessation testing moment. Patients
are divided into two groups based on the pharmacodynamic properties of their
medications. One group will consist of patients using a benzodiazepine or a
Z-hypnotic, while the other group will include opioid users. Furthermore, a
control group will be included to match the patient sample with respect to age,
gender, and driving frequency. Control participants will be excluded if they
are currently using any psychoactive medication.

Potentially eligible participants are invited to have their medication schedule
examined and, if applicable, revised by the collaborating clinicians at the
Jessa Hospital in Hasselt. The decision to alter the patients' medication will
be made only by the physician at the Jessa hospital and will always aim to meet
the patients' best medical interest. Therefore, it might well be that it is
decided that nothing will change to the medication regimen of the patient. The
general practitioner of the patient will always be informed about any changes
to the medication regimen of the patient.

The primary source of concern for the participants* well-being is the
possibility of withdrawal effects. However, gradually tapering off the
medication should prevent or minimize the occurrence of withdrawal effects.
Secondarily, fatigue due to testing can also occur. However, sufficient breaks
are included during which drinks and snacks are provided. Finally, simulator
testing can induce complaints similar to motion sickness. Participants will be
informed of this possibility before test initiation. Participants will also be
informed that they can decide to stop simulator testing whenever they feel too
uncomfortable to continue. In addition, the test supervisor will stop the
testing whenever visible signs of discomfort occur.