title: Does a medicinal dose of kava impair driving? A randomized, placebo-controlled, double-blind study.
abstract: BACKGROUND
  Increasing concerns over the potentially impairing effects of prescriptive sedative drugs such as benzodiazepines on driving have been raised. However, other alternatives such as natural medicines may also carry similar risks with respect to driving safety. Kava (Piper methysticum) is a psychotropic plant commonly used both recreationally and medicinally in the United States, Australia, and the South Pacific to elicit a physically tranquilizing effect. To date no controlled study has tested a medicinal dose of kava versus placebo and a standard sedative drug on driving ability and driving safety.
  
  
  OBJECTIVE
  Due to the need to establish the safety of kava in operating a motor vehicle, we compared the acute effects of the plant extract versus the benzodiazepine oxazepam and placebo using a driving simulator.
  
  
  METHODS
  A driving simulator (AusEd) was used by 22 adults aged between 18 and 65 years after being randomly administered an acute medicinal dose of kava (180 mg of kavalactones), oxazepam (30 mg), or placebo one week apart in a crossover design trial.
  
  
  RESULTS
  No impairing effects on driving outcomes were found after kava administration compared to placebo. Results on specific driving outcome domains revealed that the oxazepam condition had significantly slower braking reaction time compared to the placebo condition (p =.002) and the kava condition (p =.003). The kava condition had significantly fewer lapses of concentration compared to the oxazepam condition (p =.033). No significant differences were found between conditions for steering deviation, speed deviation, and number of crashes. Results were not modified by driving experience. On the Bond-Lader visual analogue sub-scale of alertness, a significant Treatment × Time interaction (p =.032) was found, with a significant reduction over time for oxazepam decreasing alertness (p <.001), whereas no significant reduction was found in the kava or placebo conditions.
  
  
  CONCLUSIONS
  The results indicate that a medicinal dose of kava containing 180 mg of kavalactones does not impair driving ability, whereas 30 mg of oxazepam shows some impairment. Research assessing larger recreational doses of kava on driving ability should now be conducted.
authors.affiliation: The University of Melbourne, Department of Psychiatry, Richmond, Melbourne, Victoria, Australia. jsarris@unimelb.edu.au
authors.forename: J
authors.initials: J
authors.lastname: Sarris
authors.forename: E
authors.initials: E
authors.lastname: Laporte
authors.forename: A
authors.initials: A
authors.lastname: Scholey
authors.forename: R
authors.initials: R
authors.lastname: King
authors.forename: A
authors.initials: A
authors.lastname: Pipingas
authors.forename: I
authors.initials: I
authors.lastname: Schweitzer
authors.forename: C
authors.initials: C
authors.lastname: Stough
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001334:Automobile Driving / Q000523:psychology*; D003198:Computer Simulation; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D020901:Kava / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010076:Oxazepam / Q000009:adverse effects; D010936:Plant Extracts / Q000009:adverse effects*; D011597:Psychomotor Performance / Q000187:drug effects*; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D010936:Plant Extracts; D010076:Oxazepam