12.4 Polypharmacy & High-Alert Medications

Polypharmacy in Older Adults

Polypharmacy is most commonly defined as the regular use of five or more medications; some definitions use ten or more as "excessive" or "hyperpolypharmacy." Age-related changes amplify the risk: decreased renal clearance and hepatic blood flow, reduced total body water and serum albumin, and increased body fat that prolongs the half-life of lipophilic drugs like diazepam. Consequences include:

• Falls and hip fractures
• Drug–drug and drug–disease interactions
• Cognitive impairment and delirium
• Poor adherence and cost burden
• Cascades of emergency visits and hospitalizations

The guiding principle for older adults is "start low, go slow" — but still titrate to effect.

Beers Criteria Highlights

The American Geriatrics Society (AGS) Beers Criteria list medications potentially inappropriate for adults 65 and older, independent of diagnosis. High-yield entries:

"Potentially inappropriate" is not "always contraindicated" — it prompts a risk–benefit review.

The Prescribing Cascade and Deprescribing

A prescribing cascade occurs when a drug's adverse effect is misinterpreted as a new medical condition and a second drug is prescribed to treat it. Classic example: an NSAID causes ankle edema → a diuretic is added → the diuretic causes gout → allopurinol is added. Another: metoclopramide causes parkinsonism → levodopa is started. The nurse's role is to ask, of every new symptom, "Could this be a medication effect?"

Deprescribing is the planned, supervised tapering or stopping of drugs whose harms outweigh benefits. Candidates include drugs without a current indication, duplicate therapies, preventive drugs with no remaining life-expectancy benefit, and sedatives in fall-prone elders. Taper where withdrawal or rebound is possible (PPIs, benzodiazepines, beta-blockers, gabapentinoids).

Medication Reconciliation at Transitions

Medication reconciliation compares the patient's actual regimen against orders at every transition — admission, transfer between units, and discharge — to catch omissions, duplications, wrong doses, and unintended interactions. Steps: build the best possible medication history (patient interview, pharmacy records, home med list), compare against new orders, resolve discrepancies with the provider, and communicate the final list to the next caregiver and the patient. Most medication errors occur at transitions, which is why reconciliation is a national patient safety goal.

A brown-bag review asks the patient to bring every bottle — prescriptions, OTC drugs, vitamins, herbals — to appointments. It reliably uncovers duplicates, expired drugs, and supplements the patient never reported.

Renal and Hepatic Dose Adjustment

• Renal: estimate kidney function (eGFR/CrCl), not just serum creatinine — an older adult with a creatinine of 1.0 mg/dL may have markedly reduced clearance because of low muscle mass. Renal-dose drugs such as gabapentin, digoxin, metformin, enoxaparin, many antibiotics, and DOACs. Metformin is withheld around iodinated contrast in patients with low eGFR because of lactic acidosis risk
• Hepatic: no single lab predicts drug metabolism; watch for hypoalbuminemia (raises free levels of highly protein-bound drugs like phenytoin), elevated INR, and bilirubin. Reduce doses of benzodiazepines, opioids, and acetaminophen in cirrhosis

Anticoagulant and Insulin Error Prevention

Anticoagulants: verify indication, renal function, platelets, and recent bleeding history; use protocol-driven dosing with independent double-checks for heparin infusions and warfarin; know the reversal agents — protamine for heparin, vitamin K ± PCC/plasma for warfarin, idarucizumab for dabigatran, andexanet alfa for apixaban/rivaroxaban. Never give IM injections to anticoagulated patients, and use electric razors and soft toothbrushes.

Insulin: the most error-prone inpatient drug. Safeguards: two-clinician independent double-check of every dose, insulin pens or syringes dedicated to insulin only (never draw from a pen), confirm the type — rapid (lispro), short (regular), intermediate (NPH), long (glargine, which is never mixed in a syringe and never given IV) — and match mealtime insulin to the actual meal. When mixing NPH with regular/rapid insulin, draw up clear before cloudy. Always have a hypoglycemia protocol: 15–20 g fast carbohydrate for a conscious patient; IV dextrose or glucagon if unconscious or NPO.

Herbal-Supplement Interactions

Patients rarely volunteer supplement use — ask directly. High-yield interactions:

• St. John's wort — potent CYP3A4 inducer: lowers levels of warfarin, oral contraceptives, transplant drugs, and many others; combined with SSRIs it can cause serotonin syndrome
• Ginkgo biloba, garlic, ginseng, high-dose vitamin E, fish oil — increase bleeding risk with warfarin, DOACs, and antiplatelets; stop before surgery per surgical protocol
• Licorice — hypokalemia and hypertension
• Ephedra (ma huang) — hypertension and arrhythmias; banned in supplements but still encountered
• Kava — hepatotoxicity, additive sedation

Patient Teaching for Complex Regimens

• Use teach-back — ask the patient to explain the regimen in their own words; this verifies understanding rather than assuming it
• Simplify: consolidate dosing times, use pill organizers or blister packs, align refills
• Provide a current written medication list to carry to every appointment
• Teach which symptoms warrant calling the provider (bleeding on anticoagulants, hypoglycemia signs on insulin, dizziness on antihypertensives)
• Address cost and health literacy directly — nonadherence is often economic, not willful
• Include a caregiver when cognition is impaired, and schedule follow-up review after any hospitalization