People living with dementia are nine times more likely to be prescribed with the antipsychotic drug risperidone while generally less likely to be given prescribed cardiovascular or respiratory treatments, an Australian study has found.
At the same time, the study of hundreds of residential nursing homes also reveals the group of more advanced dementia patients are also more likely to be medicated for urinary tract infections – another sign of reduced awareness and communication of the needs of these residents.
“While we can’t be certain of the reasons for this difference, it is possible that greater confusion or worsening cognition in residents with dementia is sometimes being attributed to urinary tract infections, prompting an increase in treatment and testing,” says geriatric clinician Dr Craig Whitehead, who worked on the study led by the Rehabilitation, Aged and Extended Care research group at the Flinders University College of Medicine and Public Health.
In all, about 25% of residents of aged-care homes receive risperidone, a drug used to manage changed behaviour.
Differences in over-prescription and under-prescription may reflect reduced awareness of, or ability to communicate, symptoms by those residents living with dementia, researchers at Flinders and Sydney University say.
“Awareness by clinicians and pharmacists of these patterns of medication use could improve management of this vulnerable population,” Dr Whitehead says.
More than 436,000 Australians are living with dementia, with numbers predicted to rise above 589,000 people by 2028 and above 1 million people by 2058.
The Flinders study, with key collaborators at the NHMRC Cognitive Partnership Centre at the University of Sydney, investigated dispensing data from the individual pharmacy records of 541 residents (average age 85.5 years and 74.5% female) at 17 Australian not-for-profit nursing homes.
Of these, 348 (64.3%) had dementia and 193 did not have dementia.
The study found nursing home residents living with dementia are more likely to be prescribed medications for treatment of behavioural and psychological symptoms of dementia, pain and urinary tract infections, than for those without dementia.
Of an average 14.5 different prescriptions over a year, about 95% of study participants were prescribed medications for the nervous system and 94% were prescribed medications for alimentary tract and metabolism.
The next most common medication classes were those for cardiovascular system (72.1%), anti-infectives for systemic use (68.9%) and dermatologicals (54.1%).
The most frequent comorbidities were osteoarthritis (48.4%), hypertension (47.1%), depression (42.9%), urinary incontinence (39.2%), and faecal incontinence (22.5%).
However, those with dementia were less likely to have comorbidities of airway diseases, angina, back pain, congestive cardiac failure, diabetes mellitus, dysphagia, hypertension, ischaemic heart disease, osteoarthritis, rheumatoid arthritis and stroke, but were more likely to have faecal or urinary incontinence.
In all, 98% of residents were prescribed more than five different medications, and 71% were prescribed more than 10 different medications over the 12-month period.
The research paper, ‘Patterns of medication prescription by dementia diagnosis in Australian nursing home residents: a cross-sectional study’, by Enwu Liu, Suzanne M Dyer, Craig Whitehead, Lisa Kouladjian O’Donnell, Emmanuel S Gnanamanickam, Stephanie L Harrison, Rachel Milte and Maria Crotty, has been published in the Journal of Pharmacy Practice and Research.
This study was funded by the National Health and Medical Research Council (NHMRC) Partnership Centre on Dealing with Cognitive and Related Functional Decline in Older People (CDPC; Grant No. GNT9100000)