In a study examining how alcohol use affects back pain, researchers at the University of Michigan Health System also found people with chronic back pain who reported heavy drinking showed less physical disability on a series of functional tests than light drinkers. Further, women seldom reported heavy alcohol use, suggesting doctors need to be more careful about prescribing narcotic pain relievers.
"Be careful if you're a heavy drinker with pain, because doctors don't seem to pay attention to the interaction between alcohol and drugs," says study co-author Andrew Haig, M.D., associate professor of Physical Medicine and Rehabilitation at the U-M Medical School and director of the Spine Program at UMHS.
"The combination of alcohol and narcotics increases the sedative effect of both, probably the desired effect amongst people with pain, but in significant quantities the combination could lead to respiratory depression," says study co-author Ethan Booker, M.D., an emergency medicine resident at the University of Chicago. In addition, painkillers that combine acetaminophen and narcotics, such as Vicodin, could cause severe liver damage when mixed with alcohol.
The study, published in the December issue of Disability and Rehabilitation, is the first to look at the relationship between alcohol and chronic back pain. It looked at 283 patients who had debilitating back pain for at least three months. Patients underwent a comprehensive assessment that included psychological tests, questionnaires related to medical history and pain, and a half-day of functional testing with rehabilitation professionals. The physical testing included exercises and tasks designed to assess the level of disability.
One of the questionnaires asked patients to rate their alcohol consumption. Of the 132 women who responded, more than three-quarters reported no alcohol use with the remaining women reporting one to five drinks per week. No women reported drinking more than five drinks per week. Because alcohol use was self-reported, the study authors suggest some women may have downplayed their actual consumption.
Of the 137 men who responded, 85 percent said they consumed five or fewer alcoholic drinks each week. Ten men reported drinking six to 11 drinks and 10 men reported 12 or more drinks. The researchers analyzed only the men's data because no women reported heavy drinking.
The study found no difference in the use of narcotic pain relievers by people who claimed heavy alcohol use and people who reported light drinking. This suggests patients or their doctors are not heeding drug manufacturers' warnings against mixing alcohol and narcotics.
"Most doctors probably do ask their patients in general terms about alcohol use, but they may not be very sophisticated in their approach to quantifying alcohol use and asking about interactions between alcohol and physical disability," says Booker, a U-M Medical School graduate.
People who drank higher quantities of alcohol were less likely to use NSAIDs such as aspirin or ibuprofen to control pain, according to study results. NSAIDs, or non-steroidal anti-inflammatory drugs, can cause stomach ulcers, and study authors suggest men who drank heavily may have stopped taking NSAIDs because of stomach irritation from combining alcohol with the pain drug.
The study also found that despite similar levels of pain, men who had more than 12 drinks a week performed better on tests of physical function that include stooping, twisting, kneeling, squatting and lifting. While they demonstrated more physical ability than the lighter drinkers, heavy drinkers were still significantly below the function of people without back pain.
Heavy drinkers, however, did not perform as well as lighter drinkers on psychosocial measures to evaluate mental health, emotional health and social functioning.
The improved performance seems to contradict the effects of alcohol, which is known to impair physical performance. Researchers suggest heavy drinkers are more at risk for disability, given the same pain and tissue damage. In other words, heavy drinkers with back pain may be partly disabled by the alcohol.
"I've had many patients tell me that they drink more because of pain. Since chronic alcohol use doesn't decrease pain, I suspect an increase in drinking is a coping mechanism for the stresses involved in having a disability," Haig says.
Funding for the study came from the Michigan Rehabilitation Engineering Research Center and the National Institute for Disability and Rehabilitation Research. In addition to Haig and Booker, study authors include Michael E. Geisser, M.D., associate professor of Physical Medicine at Rehabilitation at UMHS, and Spine Program research associate Karen Yamakawa.
Reference: Disability and Rehabilitation, 2003; Vol. 25, No. 22, 1271-1277