Polypharmacy information

Polypharmacy (polypragmasia) is an umbrella term to describe the simultaneous use of multiple medicines by a patient for their conditions.^[1][2] The term polypharmacy is often defined as regularly taking five or more medicines but there is no standard definition and the term has also been used in the context of when a person is prescribed 2 or more medications at the same time.^[1][3][4] Polypharmacy may be the consequence of having multiple long-term conditions, also known as multimorbidity and is more common in people who are older.^[5][6] In some cases, an excessive number of medications at the same time is worrisome, especially for people who are older with many chronic health conditions, because this increases the risk of an adverse event in that population.^[7][8] In many cases, polypharmacy cannot be avoided, but 'appropriate polypharmacy' practices are encouraged to decrease the risk of adverse effects.^[9] Appropriate polypharmacy is defined as the practice of prescribing for a person who has multiple conditions or complex health needs by ensuring that medications prescribed are optimized and follow 'best evidence' practices.^[9]

The prevalence of polypharmacy is estimated to be between 10% and 90% depending on the definition used, the age group studied, and the geographic location.^[10] Polypharmacy continues to grow in importance because of aging populations. Many countries are experiencing a fast growth of the older population, 65 years and older.^[11][12][13] This growth is a result of the baby-boomer generation getting older and an increased life expectancy as a result of ongoing improvement in health care services worldwide.^[14][15] About 21% of adults with intellectual disability are also exposed to polypharmacy.^[16] The level of polypharmacy has been increasing in the past decades. Research in the USA shows that the percentage of patients greater than 65 years-old using more than 5 medications increased from 24% to 39% between 1999 and 2012.^[17] Similarly, research in the UK found that the number of older people taking 5 plus medication had quadrupled from 12% to nearly 50% between 1994 and 2011.^[18]

Polypharmacy is not necessarily ill-advised, but in many instances can lead to negative outcomes or poor treatment effectiveness, often being more harmful than helpful or presenting too much risk for too little benefit. Therefore, health professionals consider it a situation that requires monitoring and review to validate whether all of the medications are still necessary. Concerns about polypharmacy include increased adverse drug reactions, drug interactions, prescribing cascade, and higher costs.^[19] A prescribing cascade occurs when a person is prescribed a drug and experiences an adverse drug effect that is misinterpreted as a new medical condition, so the patient is prescribed another drug.^[20] Polypharmacy also increases the burden of medication taking particularly in older people and is associated with medication non-adherence.^[21]

Polypharmacy is often associated with a decreased quality of life, including decreased mobility and cognition.^[22] Patient factors that influence the number of medications a patient is prescribed include a high number of chronic conditions requiring a complex drug regimen. Other systemic factors that impact the number of medications a patient is prescribed include a patient having multiple prescribers and multiple pharmacies that may not communicate.

Whether or not the advantages of polypharmacy (over taking single medications or monotherapy) outweigh the disadvantages or risks depends upon the particular combination and diagnosis involved in any given case.^[23] The use of multiple drugs, even in fairly straightforward illnesses, is not an indicator of poor treatment and is not necessarily overmedication. Moreover, it is well accepted in pharmacology that it is impossible to accurately predict the side effects or clinical effects of a combination of drugs without studying that particular combination of drugs in test subjects. Knowledge of the pharmacologic profiles of the individual drugs in question does not assure accurate prediction of the side effects of combinations of those drugs; and effects also vary among individuals because of genome-specific pharmacokinetics. Therefore, deciding whether and how to reduce a list of medications (deprescribe) is often not simple and requires the experience and judgment of a practicing clinician, as the clinician must weigh the pros and cons of keeping the patient on the medication. However, such thoughtful and wise review is an ideal that too often does not happen, owing to problems such as poorly handled care transitions (poor continuity of care, usually because of siloed information), overworked physicians and other clinical staff, and interventionism.