Polypharmacy from a pharmacist’s perspective (Part 2)
This is a continuation of last week’s article. As discussed last week, medication has greatly improved our life expectancy and quality of life; however, the increase in use of numerous medications has many possible negative health consequences. Polypharmacy is the prescribing of too many unnecessary or inappropriate medicines.
Risk of Drug interactions
A 2013 study of older hospitalised adults taking 5 or more medications indicated drug-drug interaction was as much as 80%. The probability of a drug-drug interaction increased with the number of medications prescribed. To be more specific, a patient prescribed 5-9 medications had a 50% probability of drug-drug interactions whereas this probability increased to 100% for patients taking 20 or more medications.
Non-compliance is means not taking medications as directed and is associated with complicated medication regimens and polypharmacy. This is an area where the pharmacist has an important role; non-compliance can be significantly reduced where there is pharmacist counselling (including full explanation of what each medication is for), regular medication reviews and the use of compliance aids such as blister packing of medications. Non-compliance with medication regimes risks potential disease progression, treatment failure, hospitalisation and more potential for side effects.
Polypharmacy can cause functional decline in older patients. One study indicated increased prescription medication diminished patients’ ability to perform instrumental activities of daily living (IADLs) and decreased physical functioning. IADLs refers to everyday activities like getting in and out of bed, in and out of chairs, feeding, personal hygiene etc.
A study of 294 older people showed 22% of those taking 5 or less medications had impaired cognition as opposed to 33% of patients taking 6-9 medications and 54% in patients taking 10 or more medications. This is a double edge sword as while polypharmacy increases the risk of cognitive impairment, medication is often prescribed to counteract or slow down cognitive impairment (e.g. dementia, stroke) which increases number of medications prescribed.
As the number of medications increased, the falls risk increases. The use of 4 or more medications seems to be especially associated with increased risk of falling and the risk of recurrent fall. A study of older adults in residential care settings indicated the risk of experiencing a fall within the previous 30 days was by 7% for each additional medication.
Polypharmacy can affect patients’ nutritional status. A three-year study found that 50% of those taking 10 or more medications showed signs of malnourishment. Polypharmacy in older patients is associated with reduced intake of fibre, fat-soluble and B vitamins, and minerals as well as increased intake of cholesterol, glucose, and sodium. Almost half of women and a third of men reporting polypharmacy in Ireland take food supplements regularly such as calcium (with or without vitamin D), Omega-3’s and Glucosamine.
Frequent review of the person’s medication is essential to prevent unnecessary prescriptions and the harm this can cause. The pharmacist has an important role in reducing risks in reducing over-prescribing, especially in older patients who can be more susceptible to adverse effects.
References available upon request
For comprehensive and free health advice and information call in to Whelehans, log on to www.whelehans.ie or dial 04493 34591 (Pearse St) or 04493 10266 (Clonmore).