Polypharmacy: Appropriate and Problematic

The term polypharmacy dates back at least to the mid-19th century and has had many definitions. Usually it refers to more than four or five medications used concurrently.

Issue

Recent adoption of the terms "appropriate polypharmacy" and "problematic polypharmacy" reflect both the realities of treating multi-morbidity in the population and the potential harm associated with prescribing multiple medications to some individuals, particularly frail older persons and those with cognitive disorders.¹

Bottom Line

Polypharmacy may be appropriate in managing multiple comorbidities such as diabetes, cardiovascular disease and COPD when, by following disease-specific guidelines concurrent prescription of eight or more medications may be justified. These drugs may be considered appropriate when they are prescribed and used according to best evidence, and when they improve longevity without adverse effects and negative impact on quality of life.

The term problematic polypharmacy describes circumstances when

• Multiple medications are prescribed or used inappropriately.
• Medication use is not based on evidence of efficacy for the condition or for the individual for whom they are prescribed.
• The intended benefit of medication is not realized.
• The risk of harm from a drug, or combinations of drugs, outweighs the benefits or is likely to result in unwanted drug interactions.

Achieving a balance that is acceptable both to the patient and one prescriber is a challenge which is further compounded when multiple prescribers are involved in the care of an individual patient. This becomes a particular concern when patients transition from home to hospital and back or into residential care, and when the receiving physicians may be reluctant to alter an existing drug regimen.

While the focus on polypharmacy is often on the prescriber, it should be noted that patient non-adherence with prescribed medications may sometimes be protective. Individuals who note adverse effects from certain prescribed medications may themselves reduce the dose or cease using it. When admitted to hospital or to a care facility and, for the first time, receive all prescribed drugs in full doses, the patient may then develop adverse effects.

Problematic polypharmacy includes use of drugs, alone or in combination, with high propensity for causing adverse reactions in older individuals. In addition to prescribed drugs many older individuals use over-the-counter preparations and herbal remedies which interact with prescribed drugs. While a wide range of adverse drug effects may manifest in elderly people, particular attention should be directed to those that impair independent function and may result in avoidable hospitalization. This includes drugs that impair cognitive function, alter balance and mobility, leading to falls and injury, and those that impair urinary continence. “Prescribing cascade” describes the addition of a new drug to treat symptoms that are potentially iatrogenic resulting from other drugs or drug combinations. It is most commonly found in older persons. Thoughtful review of medications at each encounter and particularly when new symptoms arise should lead to consideration of de-prescribing or at least trial withdrawal or dosage reduction of drugs most likely responsible for new symptoms.

A number of prescribing indicators have been used to identify problematic or inappropriate polypharmacy and provide guidance as to appropriate prescribing¹, One of earliest was the Medication Appropriateness Index which requires clinicians to rate explicit criteria to determine whether a medication is appropriate, marginally appropriate or inappropriate for an individual². More recently, and familiar to many prescribers, are the Beer’s criteria for potentially inappropriate medication use in older adults, reference³ and the STOPP/START (Screening Tool of older Peoples Potentially Inappropriate Prescribing/Screening Tool to Alert Doctors to Right Treatment Criteria⁴. These two tools appear to have greatest appeal to the busy clinician. Other published prescribing tools for clinicians include the PINCER indicators⁵; IPET⁶ and Prescribing Indicators, a tool for Elderly Australians⁷.

A pragmatic support for appropriate prescribing is provided in a "Stopping Medicines report from Wales⁸. It suggests eight questions that a clinician might ask regarding the value of continued drug therapy. They include: whether the drug is being used to treat an iatrogenic problem; changes in evidence in clinical guidelines; anticipated effects of discontinuation; and ethical issues around withholding care.

Choosing Wisely, launched in the United States in 2012, now in Canada⁹ and spreading world-wide, challenged National Medical Specialty Societies to create lists of evidence-based recommendations regarding treatments and investigations which practitioners in their field may overuse and which physicians and patients should discuss and consider carefully. American and Canadian geriatric and psychiatric associations made clear recommendations regarding avoidance or caution in using antipsychotics in older patients, particularly those with dementia. Other drugs of concern in older patients include benzodiazepines, hypnotics, opioid analgesics, older treatments for the overactive bladder, tricyclic antidepressants and antihistaminic, antihypertensive and hypoglycemic drugs.

Drugs with anticholinergic activity have greater potential for both systemic as well as central nervous system adverse effects in older persons and particularly those who are frail or have dementing disorders. The anticholinergic effects of tricyclic antidepressants and other drugs such as solifenacin, tolterodine, quetiapine, olanzapine and hydroxyzine are well-known. Other pharmaceuticals’ commonly prescribed for cardiovascular disease such as digoxin and furosemide and warfarin, and for other disorders have possible anticholinergic activity. Anticholinergic burden is summative and more likely to result when multiple drugs, even those with lower levels of anticholinergic activity are used in combination. A useful anticholinergic cognitive burden scale rates commonly use drugs in categories and permits an anticholinergic burden score to be calculated¹⁰. This enables prescribers to determine the drugs most likely to be contributing to cognitive decline or peripheral anticholinergic symptoms, and to prioritize dosage reduction or discontinuation.

Medication reconciliation is defined as “systematic and comprehensive review of all the medications a patient is taking to ensure that medications being added, changed or discontinued are carefully assessed and documented.”¹¹. It focuses on ensuring that medications received in one care setting are continued in the new setting. “If it's on the list, it won't be missed”¹² is a first step in avoiding problematic polypharmacy. The next step, structured medication review and planned medication optimization, that involves the patient, caregiver and, where appropriate, other health care providers can reduce the hazards of inappropriate polypharmacy through drug dosage reduction and discontinuation. “If it won't be missed, strike it from the list" may serve as a useful reminder to busy clinician.

References

• Duerden M, Avery T, Payne R. Polypharmacy and medicines optimization: Making it safe and sound. The King’s Fund 2013 ISBN: 978 1 909029 18 7.
• Hanlon JT, Schmader KE, Samsa GP. ‘A Method for assessing drug therapy appropriateness’. Journal of Epidemiology 1992 vol 45, 99 1045-51.
• Fick D, Selma T, Beizer J, et al. American Geriatrics Society updated Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2012 Apr;60(4):616-31. doi: 10.1111/j.1532-5415.2012.03923.x. Epub 2012 Feb 29.
• Gallagher P, et al. STOPP (Screening Tool of Older Person’s Prescriptions) and START (Screening Tool to Alert doctors to Right Treatment). Consensus validation. International Journal of Clinical Pharmacology and Therapeutics 2008, vol 46, pp 72-83
• Avery AJ, et al. A pharmacist-led information technology intervention for medication errors (PINCER): a multicenter, cluster randomized, controlled trial and cosdt-effective analysis. The Lancet, 2012a, vol 329, pp 1310-9.
• Naugler CT, et al. Development and validation of an improving prescribing in the elderly tool. Canadian Journal of Clinical Pharmacology, vol 7, no 2, pp 103-7.
• Basger BJ, et al. Inappropriate medication use and prescribing indicators in elderly Australians: development of a prescribing indicators tool. Drugs Aging, 2008, vol 25, no 9, pp 777-93.
• WeMeRec. ‘Prescribing for Older People’. 2011 Welsh Medicines Centre Bulletin (online). Available at: www.wemerec.org.( Accessed 2015.09.15)
• http://www.choosingwiselycanada.org/ ( Accessed 2015.09.15)
• http://www.agingbraincare.org/uploads/products/ACB_scale_-_legal_size.pdf (Accessed 2015.09.15)
• https://www.accreditation.ca/sites/default/files/med-rec-en.pdf (Accessed 2015.09.15)
• http://www.albertahealthservices.ca/hp/if-hp-medrec-public-posters.pdf ( Accessed 2015.09.15)