Polypharmacy and Medication Safety in Older Adults

Polypharmacy and Medication Safety in Older Adults

Older adults are the highest consumers of prescription medications in the United States. When a patient takes five or more medications simultaneously, this is called polypharmacy. Polypharmacy is common among geriatric residents because many have multiple chronic conditions, each managed with one or more drugs. As an LPN, you are a frontline safeguard against medication errors and adverse drug reactions (ADRs) in this vulnerable population.

Age-Related Pharmacokinetic Changes

Pharmacokinetics describes how the body absorbs, distributes, metabolizes, and eliminates drugs. Aging alters every phase of this process.

Absorption is generally the least affected phase, though reduced gastric acid and slowed gastrointestinal motility can slightly delay the onset of some oral medications.

Distribution changes significantly. Older adults have less body water and lean muscle mass but proportionally more body fat. Water-soluble drugs (such as many antibiotics) reach higher concentrations because they have a smaller volume to distribute into. Fat-soluble drugs (such as some sedatives and benzodiazepines) accumulate in fatty tissue and may have a prolonged duration of action, increasing sedation and fall risk.

Hepatic metabolism declines with age. The liver shrinks in mass and receives less blood flow, so first-pass metabolism of many drugs is reduced. Drugs that normally undergo extensive liver processing may reach higher blood levels than expected.

Renal clearance is the most clinically important change. Glomerular filtration rate (GFR) decreases with age even in otherwise healthy individuals. Many drugs and their active metabolites are cleared by the kidneys; reduced clearance means drugs linger longer, raising the risk of toxicity. Digoxin, many antibiotics, and certain pain medications are classic examples where dosing must be adjusted for renal function.

Clinical implication for the LPN: Always consider that a "standard" adult dose may be too high for a geriatric resident. Report signs of toxicity (confusion, sedation, falls, irregular heart rate, nausea) promptly. Know your resident's most recent renal function lab values and note them when reviewing the medication administration record (MAR).

The Beers Criteria

The American Geriatrics Society (AGS) publishes the Beers Criteria, a regularly updated list of medications that are potentially inappropriate for older adults. These drugs carry risks that often outweigh their benefits for this age group. The LPN's role is not to stop medications unilaterally but to recognize Beers Criteria drugs, monitor for ADRs, and communicate concerns to the licensed provider.

Key categories on the Beers Criteria include:

1. Anticholinergic agents — Drugs such as diphenhydramine (found in many over-the-counter sleep aids and antihistamines) block acetylcholine receptors. In older adults this causes confusion, urinary retention, constipation, dry mouth, and increased fall risk. The cumulative effect of taking multiple anticholinergic drugs is called anticholinergic burden.

2. Benzodiazepines and non-benzodiazepine sleep aids (Z-drugs) — Agents such as diazepam, lorazepam, and zolpidem cause sedation and impaired balance, dramatically increasing fall and fracture risk. Fat-soluble benzodiazepines accumulate in older adults due to increased body fat.

3. First-generation antipsychotics — Drugs such as haloperidol carry risks of extrapyramidal effects, sedation, and QT prolongation in older adults.

4. Non-steroidal anti-inflammatory drugs (NSAIDs) — Ibuprofen and naproxen increase risk of gastrointestinal bleeding, fluid retention, and acute kidney injury, especially in elders with already-reduced renal function.

5. Sulfonylureas (long-acting) — Agents such as glibenclamide (glyburide) have prolonged action in older adults, raising hypoglycemia risk.

6. Muscle relaxants — Cyclobenzaprine and similar agents cause sedation and confusion; their anticholinergic effects add to fall risk.

7. Digoxin at higher doses — Due to reduced renal clearance, digoxin accumulates and can cause toxicity (bradycardia, nausea, visual changes, confusion).

When you recognize a Beers Criteria medication on the MAR, your nursing actions include: monitoring for listed adverse effects, documenting observations, educating the resident and family, and reporting concerns to the charge nurse or prescriber.

The Seven Rights of Medication Administration

The classic Five Rights are:

1. Right patient

2. Right medication

3. Right dose

4. Right route

5. Right time

For geriatric medication safety, add two additional checks:

6. Right reason — Verify that the drug is appropriate for the resident's current condition. Question medications that no longer match the active diagnosis list.

7. Right documentation — Document immediately after administration, never before. Accurate documentation prevents double-dosing, which is especially dangerous in elders who clear drugs slowly.

Special Considerations When Administering Medications to Older Adults

• Swallowing difficulties (dysphagia): Ask the nurse about liquid formulations or whether tablets may be crushed. Never crush sustained-release or enteric-coated tablets without verification — doing so can cause a dangerous rapid release of medication.
• Low body weight: Weight-based dosing produces higher concentrations in a smaller body. Double-check calculations.
• Cognitive impairment: Confirm the resident has actually swallowed each dose. Offer one medication at a time if needed.
• Fall prevention: Administer sedating or blood-pressure-lowering medications at times that minimize fall risk (e.g., at bedtime when appropriate).
• Patient education: Use plain language; involve caregivers; confirm understanding with teach-back.

Patient safety is the foundation of geriatric medication care. Your vigilance — recognizing high-risk drugs, performing accurate calculations, applying the seven rights, and communicating findings — directly prevents harm.