By Lorraine L. Janeczko
ATLANTA—Almost half of U.S. Medicare beneficiaries with Parkinson's disease (PD) and dementia are prescribed medications that should never be given together, according to a study presented at the 2018 Annual Meeting of the American Neurological Association (ANA) in Atlanta.
"Among the Medicare population with Parkinson's disease, almost 45% of acetylcholinesterase inhibitor (ACHEI) users were concurrently prescribed a high-potency anticholinergic (ACH)," lead author Dr. Sneha Mantri of the University of Pennsylvania Perelman School of Medicine in Philadelphia told Reuters Health in an interview.
"ACHEIs and ACHs have opposing pharmacological actions, and prescribing them together is a 'never event' - providers should never do this. Patients who take ACHEIs and ACHs together are more likely to have delirium and are more likely to fall," she explained. "In our study, this inappropriate combination was more likely to occur in women than in men and in Hispanic than in white patients, and it tended to decrease with increasing age."
Using fiscal year 2014 Medicare claims data of the 268,407 patients with PD, Dr. Mantri and colleagues investigated risk factors for co-prescribing a high-potency ACH and ACHEI (an ACHhigh-ACHEI event) to patients with PD and dementia.
The research team reviewed the records of patients who received one or more prescriptions for an anti-dementia drug and had one or more ACHhigh-ACHEI events that year.
Overall, 27.2% of Medicare patients were prescribed at least one anti-dementia medication, most commonly donepezil (63.0% of users), memantine (41.8% of users), and rivastigmine (26.4% of users).
Drugs for dementia were more likely to be prescribed to African Americans than whites (adjusted odds ratio (AOR) 1.33) and Hispanics (AOR 1.28). The drugs were also less likely to be prescribed to North American Natives (AOR 0.62) and those of other or unknown ethnicities (AOR 0.84). Females were less likely than males to be prescribed a drug for dementia (AOR 0.85).
Of the 64,017 PD patients who were taking an ACHEI, 28,495 (44.5%) experienced one or more ACHhigh-ACHEI events. Hispanic patients (AOR 1.11) and females (AOR 1.30) were most likely to experience this 'never event.'
ACHhigh-ACHEI events were most common in the Midwest and South and varied widely by area of the country.
"This polypharmacy issue comes up often when we see patients in a clinical setting and review their medicines. They may be on a laundry list of medications and frequently are on medicines with competing modes of action," Dr. Mantri explained.
"The extent of the disparities in care surprised me," she said. "The fact that, for instance, women were 30% more likely to have this kind of potentially inappropriate prescribing compared to men is a real area of concern."
"Similarly," she added, "the place where you live makes a huge difference in prescribing habits. The extent to which those differences exist is really shocking."
"We do a good job of recognizing dementia in our patients and prescribing the correct medications. But we need to expand our attention beyond the medications we personally are prescribing," Dr. Mantri advised. "At each visit, providers should review with their patients all the medications they are taking. Providers should specifically ask about all medications, including over-the-counter and herbal medicines."
Dr. Mantri also advises that electronic medical records flag the combination of acetylcholinesterase inhibitor plus anticholinergic to help avoid this "never event."
Dr. M. Elizabeth Ross, the director of the Center for Neurogenetics at Weill Cornell Medicine in New York City, told Reuters Health by email, "This is an important look into treatment disparities among over a quarter of a million Parkinson's Disease patients across ethnic groups and geographic regions in the U.S."
"The study raises interesting questions about why dementia medications are more likely to be prescribed to African American and Hispanic PD patients compared to whites," noted Dr. Ross, who is the scientific program advisory committee chair of the American Neurological Association but was not involved in the study.
"It also raises questions about whether these practices reflect differences in clinical symptoms or expectations of patients and family members," she added, "or whether access to adjunctive measures such as nutritional and physical therapy has an impact on clinical management in these groups."
The National Institute of Neurological Diseases and Stroke (NINDS) of the National Institutes of Health (NIH) funded the study.
American Neurological Association 2018.
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