Regular administration of acetaminophen raises levels of general activity, social interaction, engagement with media such as television or magazines, and worklike activity in elderly patients with moderate to severe dementia, reported John T. Chibnall, Ph.D., of St. Louis University School of Medicine, and his associates.
Regular dosing with the analgesic presumably addresses untreated pain in these patients, who often cannot report pain and who have a high prevalence of comorbidities, including arthritis, fractures, and diabetes, which can generate significant pain, the researchers said.
Their study findings imply that untreated pain inhibits dementia patients' active engagement with the environment and promotes their withdrawal, Dr. Chibnall, a professor of psychiatry at the university, and his associates added (J. Am. Geriatr. Soc. 2005;53:1921–9).
The researchers evaluated behavioral changes in 25 elderly (mean age 85.9 years) nursing home residents with moderate to severe dementia during an 8-week study. The subjects had Alzheimer's disease, degenerative dementia, or multi-infarct dementia and had resided in nursing homes for a mean of 35 months. All had moderate to severe cognitive decline and impairment in the activities of daily living.
The subjects were given either two 500 mg tablets of acetaminophen or two placebo tablets at mealtimes every day for 4 weeks, then switched to the other treatment for 4 weeks, following a 1-week washout period between the two phases.
Their behavior was evaluated under both conditions using the Dementia Care Mapping (DCM) tool, in which trained “mappers” observed patients for 5 hours between 9 a.m. and 2 p.m., when subjects were likely to be most active. At 5-minute intervals, the observers quantified a wide range of behaviors across 24 domains such as direct or passive social involvement, creative activities, exercise, listening to music, and eating.
The subjects also were evaluated using the Cohen-Mansfield Agitation Inventory (CMAI), a 29-item scale in which nursing home personnel assessed how often the patients had displayed a variety of agitated behaviors during the preceding 2 weeks.
With acetaminophen, subjects clearly showed higher levels of general activity, spent more time in direct social interactions and in engagement with media, and participated more in worklike activity. They also spent significantly less time alone in their rooms.
However, subjects also spent more time in passive social involvement, more time talking to themselves or to imaginary others, and slightly more time experiencing unattended distress while on acetaminophen.
Agitation did not decrease, and the use of both routine and as-needed psychotropic medications did not decrease, while the subjects were taking acetaminophen. However, the levels of agitation and the frequency of agitated behaviors were quite low in this study, which may have confounded the results. Similarly, the use of psychotropic drugs was quite low overall, leaving little room for the intervention to show an effect, the researchers noted.
Overall, the results support the contention that pain dampens dementia patients' activity and restricts their engagement with the environment, while prophylactic treatment of that pain reverses these effects.