The risk of traffic accidents after prescriptions of carisoprodol.
OBJECTIVE
Carisoprodol, a drug used for acute lower back pain, may cause psychomotor impairment. We wanted to investigate if patients using carisoprodol had increased risk of being involved in a traffic accident.


METHODS
Data were retrieved from three population-based registries for the period April 2004-September 2005. The Norwegian Prescription Database contained individual information on all dispensed drugs at all pharmacies outside hospitals. The Norwegian Road Accident Registry contained information on all drivers involved in motor vehicle accidents with person injury. The Norwegian Central Population Registry was used to control for emigration or death. The accident incidence among carisoprodol exposed and unexposed subjects was compared by standardized incidence ratio.


RESULTS
Having a prescription for carisoprodol dispensed increased the standardized incidence ratio for being involved in an accident with person injury to 3.7 (95% CI 2.9-4.8) the first week after the date of dispensing. This was similar to diazepam (2.8; 2.2-3.6), but higher than for salbutamol (1.1; 0.6-1.8).


CONCLUSIONS
Patients receiving carisoprodol seem to have an increased risk of being involved in traffic accidents involving person injury. The study gives support to earlier work published on the impairing effects of carisoprodol.
Bramness
Jørgen G
JG
Department of Pharmacoepidemiology, Division of Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, NO-0403 Oslo, Norway. jorgen.bramness@fhi.no
Skurtveit
Svetlana
S
Mørland
Jørg
J
Engeland
Anders
A
D000063:Accidents, Traffic / Q000517:prevention & control / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000420:Albuterol / Q000009:adverse effects / Q000627:therapeutic use; D018927:Anti-Asthmatic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001416:Back Pain / Q000188:drug therapy* / Q000453:epidemiology; D001569:Benzodiazepines / Q000009:adverse effects / Q000627:therapeutic use; D002328:Carisoprodol / Q000009:adverse effects* / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D003975:Diazepam / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008620:Meprobamate / Q000009:adverse effects / Q000627:therapeutic use; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000009:adverse effects* / Q000627:therapeutic use; D009664:Norway; D016017:Odds Ratio; D012042:Registries / Q000706:statistics & numerical data
D018927:Anti-Asthmatic Agents; D009125:Muscle Relaxants, Central; D001569:Benzodiazepines; D002328:Carisoprodol; D008620:Meprobamate; D003975:Diazepam; D000420:Albuterol