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No link between opioid use, risk for Alzheimer’s disease

Opioid use is not associated with an increased risk for Alzheimer’s disease, according to findings recently published in Pain Medicine.

“Older persons frequently use opioids for long time periods,” Heidi Taipale, PhD, Pharm, of the School of Pharmacy at the University of Eastern Finland, told Healio Family Medicine. “Although opioids are known to have some impairing effects on cognitive function, the association between opioid use and dementia has rarely been investigated.”

Researchers matched participants from Finland’s nested case-control study of patients with Alzheimer’s disease known as MEDALZ (n = 70,718) with up to four region-of-residence-, sex- and age-matched persons who did not have Alzheimer’s disease (n = 282,862). The mean age of patients in the study was 80 years, and 65% were women. Exposure to opioids was determined by using Finland’s National Prescription Register. Researchers used a 3-year time window between opioid use and Alzheimer’s disease to avoid reverse causality.

Researchers also adjusted data for antipsychotic use, benzodiazepine and related drug use, CVD, diabetes, history of cancer, hospital-treated depression, number of drugs taken, rheumatoid arthritis, stroke and substance abuse.

Taipale and colleagues found that opioid use was not associated with an increased risk for Alzheimer’s disease (adjusted OR = 1; 95% CI, 0.98–1.03). In addition, neither more than 90 total standardized doses (aOR = 1.02; 95% CI, 0.98–1.07) nor cumulative use for more than 365 days (aOR = 1.02; 95% CI, 0.96–1.08) of opioids was associated with risk for Alzheimer’s disease.

“The inconsistent effects of opioids on cholinergic systems might be one reason why the long-term effect of opioids on Alzheimer’s disease seems to be neutral,” researchers wrote.

“However, it is also possible that those who had used the greatest amounts of opioids had died due to other causes, such as cancer, before reaching the advanced age when Alzheimer’s disease is most commonly diagnosed, although this is an unlikely explanation because the cases and controls were matched by age,” they continued. “In addition, opioid use patterns and traditions for long-term prescribing may differ between countries, and it is possible that the association can only be found in even higher doses than investigated in our study.”

Taipale and colleagues also wrote that it is also plausible that some long-term opioid users developed cognitive effects other than actual dementia, which went beyond the scope of the study.

She offered some suggestions on how primary care physicians can implement the study’s findings with their patients.

"Clinicians should focus on the known risks of opioids. PCPs should also keep in mind the risk for falls associated with opioid use among older persons, as well as the development of tolerance and addictive potential of these medications.” – by Janel Miller

Disclosures: Taipale reports participating in research projects funded by Janssen and Eli Lilly. Please see the study for all other authors’ relevant financial disclosures.