Reviewed by Shameer Deen, ST5 Urology Registrar
Older adults represent both the largest consumers of prescription medications and the population most vulnerable to drug-related harm. Physiological changes with ageing — reduced renal clearance, decreased hepatic mass and enzyme activity, altered body composition, diminished physiological reserve — fundamentally change how drugs behave in elderly patients [1]. A drug well tolerated in a 40-year-old may cause falls, delirium, or cardiac arrhythmias in an 80-year-old on the same dose. Safe prescribing for older adults requires a distinct skill set.
The AGS Beers Criteria
The American Geriatrics Society (AGS) Beers Criteria, last updated in 2023, provide a comprehensive list of potentially inappropriate medications (PIMs) in adults aged 65 and older [1]. The criteria are organised into several sections:
- Medications to avoid in older adults regardless of diagnosis — includes first-generation antihistamines (chlorphenamine, promethazine), muscle relaxants, most benzodiazepines, antipsychotics (except for specific indications), tricyclic antidepressants, and long-acting sulphonylureas
- Medications to avoid in specific diseases or conditions — e.g. NSAIDs in patients with CKD, history of peptic ulceration, or heart failure
- Medications to use with caution — aspirin in patients with a history of falls or peptic ulcer disease; prasugrel in patients aged 75 or older
- Drug-drug interactions to avoid — anticholinergic combinations, concurrent opioid and benzodiazepine use
STOPP/START: The European Perspective
The STOPP/START (Screening Tool of Older Persons' Prescriptions / Screening Tool to Alert doctors to Right Treatment) criteria, updated in 2023, provide a complementary European framework [2]. STOPP identifies medications that should be stopped or reconsidered in older patients, while START identifies potentially beneficial medications that are being omitted. Key STOPP signals include:
- Proton pump inhibitors at maximum therapeutic dose for more than 8 weeks without justification
- Benzodiazepines — risk of prolonged sedation, falls, road traffic accidents, delirium
- Anticholinergic drugs in patients with cognitive impairment
- Alpha-1-blockers in men with symptomatic orthostatic hypotension
- Opioids without a concurrent laxative prescription
Anticholinergic Burden
Many commonly prescribed drugs have significant anticholinergic activity, and the cumulative anticholinergic burden of a polypharmacy regimen can cause peripheral effects (dry mouth, constipation, urinary retention) and central effects (cognitive impairment, delirium, falls) [1]. Drugs with high anticholinergic burden include:
- Tricyclic antidepressants (amitriptyline, imipramine)
- First-generation antihistamines
- Bladder antimuscarinics (oxybutynin, tolterodine)
- Some antipsychotics (chlorpromazine, olanzapine)
- Antiemetics (prochlorperazine, promethazine)
- Antispasmodics (hyoscine)
Several validated tools exist to quantify anticholinergic burden, including the Anticholinergic Cognitive Burden (ACB) scale. Reducing the total anticholinergic burden of a regimen is an important intervention in older patients with cognitive concerns.
Falls-Risk Medications
Falls are the leading cause of injury-related mortality in adults over 65 [2]. Several drug classes are independently associated with increased falls risk and should be used with caution or avoided:
- Benzodiazepines and z-drugs — sedation, impaired balance and reaction time
- Antipsychotics — extra-pyramidal effects, postural hypotension
- Antihypertensives — orthostatic hypotension, particularly on initiation or dose increase
- Diuretics — volume depletion, orthostatic hypotension
- Opioids — sedation, impaired gait and proprioception
- Alpha-blockers — orthostatic hypotension
A Systematic Approach to Geriatric Medication Review
At each clinical encounter with an older patient on multiple medications, apply a structured approach: identify and stop any PIMs identified by Beers or STOPP criteria; check for beneficial drugs that are being omitted (START); calculate and seek to reduce anticholinergic burden; and review falls-risk drugs if the patient has a history of falls or postural hypotension. MedNext Formulary's drug monographs include elderly-specific cautions and dosing guidance from the MedNext Audited Proprietary Dataset to support these reviews at the point of care.
References
- American Geriatrics Society 2023 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2023;71(7):2052-2081.
- O'Mahony D, Cherubini A, Guiteras AR, et al. STOPP/START criteria for potentially inappropriate prescribing in older people: version 3. Eur Geriatr Med. 2023;14(4):625-632.