Effects of alprazolam on driving ability, memory functioning and psychomotor performance: a randomized, placebo-controlled study.
Alprazolam is prescribed for the treatment of anxiety and panic disorder. Most users are presumably involved in daily activities such as driving. However, the effects of alprazolam on driving ability have never been investigated. This study was conducted to determine the effects of alprazolam (1 mg) on driving ability, memory and psychomotor performance. Twenty healthy volunteers participated in a randomized, double-blind, placebo-controlled crossover study. One hour after oral administration, subjects performed a standardized driving test on a primary highway during normal traffic. They were instructed to drive with a constant speed (90 km/h) while maintaining a steady lateral position within the right traffic lane. Primary performance measures were the Standard Deviation of Lateral Position (SDLP) and the Standard Deviation of Speed (SDS). After the driving test, subjective driving quality, mental effort, and mental activation during driving were assessed. A laboratory test battery was performed 2.5 h after treatment administration, comprising the Sternberg Memory Scanning Test, a Continuous Tracking Test, and a Divided Attention Test. Relative to placebo, alprazolam caused serious driving impairment, as expressed by a significantly increased SDLP (F(1,19) = 97.3, p <.0001) and SDS (F(1,19) = 30.4, p <.0001). This was confirmed by subjective assessments showing significantly impaired driving quality (F(1,19) = 16.4, p <.001), decreased alertness (F(1,19) = 43.4, p <.0001), decreased mental activation (F(1,19) = 5.7, p <.03) and increased mental effort during driving (F(1,19) = 26.4, p <.0001). Furthermore, alprazolam significantly impaired performance on the laboratory tests. In conclusion, alprazolam users must be warned not to drive an automobile or operate potentially dangerous machinery.
Verster
Joris C
JC
Utrecht Institute for Pharmaceutical Sciences, Department of Psychopharmacology, University of, Utrecht, The Netherlands. J.C.Verster@pharm.uu.nl
Volkerts
Edmund R
ER
Verbaten
Marinus N
MN
D000328:Adult; D000525:Alprazolam / Q000009:adverse effects*; D014151:Anti-Anxiety Agents / Q000009:adverse effects*; D001007:Anxiety / Q000188:drug therapy*; D001143:Arousal / Q000187:drug effects / Q000502:physiology; D001288:Attention / Q000187:drug effects / Q000502:physiology; D001334:Automobile Driving / Q000523:psychology*; D002490:Central Nervous System / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects* / Q000502:physiology; D009039:Motion Perception / Q000187:drug effects / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D010919:Placebos / Q000494:pharmacology; D011596:Psychomotor Disorders / Q000139:chemically induced / Q000503:physiopathology; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology
D014151:Anti-Anxiety Agents; D010919:Placebos; D000525:Alprazolam