Potentially Harmful Medication Use in the Elderly

The American Geriatrics Society (AGS) has recently updated the Beers Criteria for potentially inappropriate medication (PIM) use in older adults. The Beers Criteria is an evidenced-based approach to identify medications that are typically best avoided in people over 65 years of age. Medications included in this criteria are associated with poor health outcomes, including confusion, falls, and mortality. Therefore, avoiding PIMs in older adults could be expected to improve care by reducing exposure to medications with an unfavourable risk to benefit ratio.

The 2019 update is the result of an extensive systematic review and grading of evidence pertaining to drug-related problems and adverse events in older adults. Several medications have been removed from the criteria for the following reasons:

• The risks associated with the drug in question were not unique to older people (e.g. the use of stimulants in people with insomnia);
• The weak nature of evidence used to support the inclusion of the drug (e.g. H₂-receptor antagonists in dementia);
• The highly specialised nature of the drug made its use fall outside the scope of the criteria (e.g. chemotherapeutic agents such as carboplatin and vincristine); and
• The drug is no longer available.

A selection of medications included in the 2019 Beers Criteria of PIMs to avoid in older adults is shown in Table 1. The complete list can be found here.

Table 1. Potentially inappropriate medications to avoid in older adults.

Abbreviations: NSAIDs, non-steroidal anti-inflammatory drugs; CNS, central nervous system; GI, gastrointestinal; CrCl, creatinine clearance.

A number of other medications have been identified as being potentially inappropriate in older adults with specific medical conditions. For example, anticholinesterases should be avoided in older adults with a history of syncope that may be due to bradycardia. Anticholinesterases such as donepezil, galantamine, and rivastigmine can produce vagotonic effects on the heart rate and worsen any pre-existing bradycardia. Other key conditions that warrant particular consideration of PIMs include heart failure, delirium, dementia or cognitive impairment, history of falls or fractures, Parkinson’s disease, history of gastric or duodenal ulcers, chronic kidney disease with a CrCl <30mL/min, urinary incontinence in women, lower urinary tract symptoms, and benign prostatic hyperplasia.

There are also a number of medications identified as being of concern in older adults, but for which the evidence is lacking to support a blanket recommendation to avoid. These agents are classified as drugs to be used with caution in older adults. A summary of these agents can be seen in Table 2.

Table 2. Drugs to be used with caution in older adults

Abbreviations: CV, cardiovascular; SNRI, serotonin and noradrenaline reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; DOAC, direct-acting oral anticoagulant; VTE, venous thromboembolism; AF, atrial fibrillation; SIADH, syndrome of inappropriate antidiuretic hormone secretion; ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor antagonist.

The Beers Criteria make additional considerations of drug interactions to avoid in older people and drugs to avoid or dose modify in older adults with reduced kidney function. Two significant additions to the drug interactions to avoid are the use of opioids with benzodiazepines and the use of opioids with gabapentinoids. Such combinations increase the risk of overdose or the risk of severe sedation-related adverse events such as respiratory depression and death. Recommendations for older adults with renal impairment include reducing the dose of enoxaparin and avoiding spironolactone, which echoes the advice contained in the respective Australian approved product information documents.

Although many of the medication issues described in the Beers Criteria are broadly applicable to patients of all ages, the elderly may be at greater risk of harms. The reasons for this are many and complex, but include physiological changes that affect drug absorption, distribution, metabolism, and excretion, and the greater incidence of polypharmacy in this patient group. The Australian Commission on Safety and Quality in Health Care reports that between 40% and 50% of residents in aged care facilities are prescribed at least one PIM.

Options to reduce the exposure to PIMs include:

• Reduce the number or dose of medications that may be causing harm. Evidence-based deprescribing guidelines can be consulted for further guidance;
• Consider safer alternatives to PIMs (e.g. a second-generation antihistamine may be preferred to a first-generation antihistamine); and
• Consideration of non-pharmacological therapies (e.g. massage, mouth care, animal-assisted therapy).

The Beers Criteria is a useful evidence-based aid that may be used to help assess the appropriateness of pharmacotherapy in older adults. However, it should be emphasised that medications identified in the criteria are potentially inappropriate rather than definitely inappropriate for all older persons. It is also important to note that the criteria was developed for the USA and is not intended to be used in hospice or palliative care settings where risk-benefit considerations may be different. In all cases, it is the clinical judgement of the prescriber in conjunction with the patient’s wishes that should guide decision making.