May 4, 2020

Polypharmacy: Definition, Causes, and Solutions

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By Lisa C. Hutchison, PharmD, MPH, BCPS, BCGP
University of Arkansas for Medical Sciences (UAMS) College of Pharmacy

 

Definitions

Polypharmacy may be defined as a number of medications, ranging from as few as two to as many as 21.  The most common numerical threshold for polypharmacy is 5-6 or more medications.  However, a patient with diabetes, chronic kidney disease, hypertension and heart failure is easily prescribed more than 6 medications if treated according to accepted guidelines making them all potentially appropriate for the individual.  Polypharmacy may be defined as use of potentially inappropriate medications as identified by a set of criteria such as the AGS 2019 Beers Criteria.(1)  These criteria list medications whose risk usually outweighs potential benefit when used in older adults.  Yet another definition of polypharmacy is limited to the presence of medications in the patient’s list that are unnecessary, which is defined as medications that are not indicated, dosed in excess, continued beyond an adequate duration, duplications, or causing adverse events.  The most stringent definition of polypharmacy involves evaluation of each medication a patient receives according to 10 questions which comprise the Medication Appropriateness Index.(2)

  • Is there an indication for the drug?
  • Is the medication effective for the condition?
  • Is the dosage correct?
  • Are the directions correct?
  • Are the directions practical?
  • Are there clinically significant drug-drug interactions?
  • Are there clinically significant drug-disease/condition interactions?
  • Is there unnecessary duplication with other drugs(s)?
  • Is the duration of therapy acceptable?
  • Is this drug the least expensive alternative compared to others of equal utility?

If any of the questions receives a negative response, the drug use is not appropriate and polypharmacy is present.  In research applications, the first three questions are given more weight in the assessment.  This helps the clinician know to focus on indication, effectiveness, and dosage.

Causes

The causes of polypharmacy are many, but include the patient’s use of multiple physicians and pharmacies, disease state guidelines recommendations for multiple medications, prescribing cascades, and direct-to-consumer advertising.  When a patient sees multiple physicians, communication between providers is necessary to prevent prescription of duplicate medications.  In addition, prescribing cascades may result when one prescriber is unaware of the therapy recommended or prescribed by a previous prescriber. Additional medications to be considered are over-the counter medications and supplements that the patient consumes without the knowledge of the provider. This results in a further increase in drug interactions and adverse drug events.  If a patient uses different pharmacies, assessment of important drug-drug interactions may be lacking as each pharmacy will likely only have a partial list of medications.(3, 4)

The prescribing cascade is defined as when a new medication is prescribed for a symptom that is misinterpreted as a new medical condition when it is actually an adverse drug reaction or side effect.  An example is shown in Figure 1.

Prevention and Intervention

The first step in prevention of inappropriate polypharmacy is to perform a medication regimen review whenever a new medication is being considered for prescription.  An adverse drug effect may be the cause of a symptom and require adjustment or discontinuation of a currently prescribed agent instead of addition of a new one.  Non-pharmacological interventions are preferred for many chronic illnesses and should be promoted to older adults.

Secondly, the clinician can identify inappropriate polypharmacy exists for an older adult through use of various tools that can aid in identifying medications that may be unnecessary.  Annual or more frequent review of the medication regimen is recommended.(5) Taking the time to carefully consider each medication and its risk/benefit in light of a patient’s circumstances is important, especially as a patient becomes frail with an increased susceptibility to adverse effects.

 

 

References:

  1. American Geriatrics Society 2019 Beers Criteria® Update Expert Panel. 2019 updated Beers Criteria® for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2019; 67:674-94 DOI: 10.1111/jgs.13702
  2. Hanlon JT, Schmader KE, Samsa GP, Weinberger M, Uttech KM, Lewis IK, et al. A method for assessing drug therapy appropriateness. J Clin Epidemiol. 1992;45:1045–51.
  3. Rochon PA, Gurwitz JH. Optimising drug treatment for elderly people: the prescribing cascade.  1997;315:1096-9.
  4. Scott IA, Gray LC, Martin JH,Mitchell CA. Minimizing inappropriate medictions in older populations: a 10-step conceptual framework.  Am J Med. 2012;125:529-37.
  5. Choosing Wisely. An initiative of the ABIM Foundation. https://www.choosingwisely.org/societies/american-geriatrics-society/ Accessed 30 April 2020.

 

Figure 1