Geriatric assessment and polypharmacy: How the Pharmacist can contribute to prescription reviews

This situation is not without consequences: drug interactions, potentially inappropriate prescribing, and adverse drug events (ADEs) are the third leading cause of preventable hospitalizations among the elderly. Faced with this challenge, the pharmacist, whether in a community or hospital setting, has specific tools and a recognized role in reviewing and optimizing geriatric prescriptions.

Understanding polypharmacy in the elderly

Aggravating factors related to aging

Physiological aging profoundly changes pharmacokinetics (what the body does to the drug) and pharmacodynamics (what the drug does to the body):

• Decreased renal function: serum creatinine levels can mask true renal impairment in the lean elderly patient. Many drugs carry an increased risk of overdose in the event of renal failure.
• Decreased hepatic function: the metabolism of numerous drugs is slowed down, increasing their half-life and plasma concentration.
• Increased adipose tissue: fat-soluble drugs (benzodiazepines, certain antidepressants) accumulate more in the tissues.
• Decreased serum albumin: the free (active) fraction of highly protein-bound drugs is increased.
• Increased sensitivity to adverse effects: particularly anticholinergic effects (confusion, urinary retention, constipation) and cardiovascular effects.

Clinical consequences of polypharmacy

Polypharmacy in the elderly is associated with a significantly increased risk of:

• Falls (hypotensive drugs, benzodiazepines, antipsychotics).
• Confusion and acute confusional state (anticholinergics, opioids, corticosteroids).
• Preventable hospitalizations (severe ADEs, cardiac decompensation).
• Non-adherence (overly complex prescriptions, too many daily doses).
• Clinically significant drug interactions.

Tools for identifying potentially inappropriate prescriptions

The pharmacist has several scientifically validated tools to identify potentially inappropriate medications for the elderly. These tools, developed from expert consensus, are gradually being integrated into community and hospital pharmacy management software.

The Beers Criteria

Developed in the United States by the American Geriatrics Society and regularly updated, the Beers Criteria lists potentially inappropriate medications. Although its context is American, it remains a useful scientific reference, particularly for drugs with anticholinergic effects and for benzodiazepines.

The anticholinergic burden scale

The cumulative anticholinergic burden of a prescription is an indicator of the risk of anticholinergic syndrome (confusion, urinary retention, constipation, dry mouth, tachycardia). Several scales allow this score to be calculated (ACB, DBI, ARS). A high score should alert the professional to the need to re-evaluate the medications.

The pharmacist's role in medication review

In the community pharmacy: the medication review

The shared medication review (SMR), which became standard practice in 2021, is the formal tool that allows the community pharmacist to conduct a structured review of the prescription, in coordination with the attending physician. For elderly patients with polypharmacy, the SMR makes it possible to:

• Inventory all medications taken (prescriptions, self-medication, dietary supplements).
• Identify therapeutic duplications and interactions (via STOPP/START criteria).
• Spot medications unsuited to current renal/hepatic function.
• Propose prescription simplifications to improve adherence.

In nursing homes (LTCFs): collaboration with the coordinating physician

In long-term care facilities, the referent pharmacist plays a central role. In collaboration with the coordinating physician, they can:

• Participate in annual reviews: provide their expertise on inappropriate prescribing within the individualized care plan.
• Analyze prescriptions for new admissions: quickly identify problems right upon admission.
• Contribute to medication policy: help define the list of preferred medications.
• Train healthcare teams: raise awareness about specific adverse effects and warning signs.

PDA as a tool for adherence and review

The Preparation of Doses to Administer (PDA) is particularly relevant in the context of geriatric polypharmacy. It facilitates the review of prescriptions:

• Visibility on complexity: during preparation, the pharmacist analyzes each dose, naturally identifying anomalies (duplications, doses, incompatibilities).
• Schedule simplification: transitioning to PDA allows for rationalizing dosage schedules with the prescriber.
• Detection of non-adherence: unconsumed returned pillboxes are valuable indicators.

Limitations and precautions

Medication review by the pharmacist has limitations that must be respected:

• The pharmacist does not prescribe: any modification must be validated by the physician.
• The tools (STOPP/START) are decision aids: a prescription deemed inappropriate may be justified by clinical elements unknown to the pharmacist.
• Collaborative approach: it must be part of an interprofessional exchange, without unilateral management.