Study investigates prescribing patterns of cognitive impairment-associated drug

Many adults with diabetes who also suffer from the complication of peripheral neuropathy often find themselves prescribed medications at doses and for durations that could potentially increase their risk of cognitive impairment. This worrying trend has prompted a new study led by Research Scientist Noll Campbell, PharmD, M.S., from the Regenstrief Institute and Purdue University College of Pharmacy, which sheds light on prescribing patterns of tricyclic antidepressants for the treatment of diabetic peripheral neuropathy.

With a study population that included adults over 18 years of age and was comprised of 44 percent White and 42 percent Black individuals, the researchers discovered that nearly two-thirds of the prescribed tricyclic antidepressants exceeded the dosage threshold associated with an increased risk of dementia in older adults. Alarmingly, Black patients were more likely to be prescribed these drugs at higher doses, significantly elevating their risk for dementia compared to their White counterparts.

Research conducted by the Regenstrief Institute has consistently shown a link between the long-term use of anticholinergic medications, such as tricyclic antidepressants, and cognitive impairment, including dementia. Studies suggest that the use of anticholinergics in older adult populations can increase the risk of dementia by 30 to 50 percent.

Diabetic peripheral neuropathy is a common syndrome among adults with long-term or uncontrolled Type I or Type II diabetes, resulting in damage to neurons that impairs neurological function in the extremities. This condition can cause pain, numbness, vulnerability to infection, and other complications. Despite current diabetes care guidelines recommending the use of tricyclic antidepressants to manage pain and concurrent depression, there is a lack of awareness regarding the risks associated with long-term usage of these drugs, which target the nerves and brain.

“Our analysis of electronic health records revealed that tricyclic antidepressants were being prescribed to individuals with diabetes for durations of up to five, eight, or even nine years, exposing about two-thirds of users to a higher risk of dementia,” explained Dr. Campbell, an expert in aging brain and pharmacy services research. “Deprescribing these medications could potentially reduce the risk of dementia, and there are alternative drugs available that do not pose a threat to cognitive function while being equally effective. Unfortunately, we found minimal evaluation of drug efficacy in routine clinical care settings.”

“Older Black adults in the U.S. are disproportionately affected by dementia compared to their White counterparts. Is this disparity due to the disease itself, or could it be attributed to the medications they are prescribed? While modifying the disease may be challenging, we have the power to alter the types of medications utilized to manage these conditions,” Dr. Campbell noted.