But, now researchers at the Rush University Medical Centre, Chicago, Illinois have found that moderate, long-term pain medication use does not hamper a person's ability to drive safely.
Asokumar Buvanendran, M.D., associate professor, Department of Anesthesiology at the University said that the study found that there was no difference in the 'driving skills and reaction times' of patients taking morphine compared to non-medicated drivers.
In the study, two groups of patients were compared.
The groups included 51 patients who were persistently received oral morphine and 49 patients; the control group received no pain medication.
The study participant were made to drive for approximately 12 minutes in a driving simulator that measured deviation from the centre of the road, weaving, the number of accidents and reaction time to surprise events.
For both sets of drivers the amount of weaving was 3.83 feet, and the opioid group had 5.33 collisions compared to the non-opioid group with 5.04.
Reaction time also was similar for both groups: 0.69 seconds for the controlled group and 0.67 for the opioid group.
Dr. Buvanendran said that the analysis suggested that patients who need, long-term pain medicine actually may 'become tolerant' to the medication side effects that potentially impair function.
Drivers under the influence of pain medication are subjected to the same laws and penalties as drivers under the influence of alcohol.
"In the future, these patients may be able to live like normal functioning people, without the stigma and limitations now associated with long-term pain medication use," Dr. Buvanendran said.