NR 565 Week 7 Polypharmacy Case Analysis Example

Case Analysis: Eleven Medicines for an 81-Year-Old After a Fall, Read as Evidence, Screened by Mechanism and Reduced by Four

Student Name

College of Nursing, Chamberlain University

NR 565: Advanced Pharmacology Fundamentals

Instructor Name

Month Day, Year

Case Analysis: Eleven Medicines for an 81-Year-Old After a Fall, Read as Evidence, Screened by Mechanism and Reduced by Four

The List as Evidence

A composite 81-year-old patient, a retired postmaster living with an adult child, is seen in a rural clinic one week after a fall at home, with bruising but no fracture. The patient has atrial fibrillation, hypertension, hyperlipidemia, mild Alzheimer disease, osteoarthritis of both knees, urinary urgency, chronic constipation and a remote history of a peptic ulcer. Weight is 64 kg and the estimated creatinine clearance is 42 mL/min. The orthostatic blood pressure falls from 134/76 lying to 112/68 standing, with dizziness.

Current medicines, as the patient's daughter reads them from the bottles: amiodarone (200 mg each morning), warfarin (5 mg each evening, latest INR 3.4), simvastatin (40 mg nightly), metoprolol succinate (50 mg), amlodipine (10 mg), donepezil (10 mg nightly), oxybutynin immediate-release (5 mg, three doses a day), omeprazole 40 mg daily for eight years, tramadol 50 mg up to four times daily, sertraline 50 mg daily and docusate 100 mg twice daily.

Screened by Mechanism

Rather than reproducing every result an interaction checker returns, the analysis groups the list by mechanism.

Shared metabolic route. Amiodarone inhibits CYP3A4, CYP2C9 and P-glycoprotein. It raises simvastatin exposure, increasing the risk of myopathy, and labeling limits simvastatin to 20 mg daily with amiodarone. It also inhibits warfarin metabolism, which explains an INR of 3.4 on a steady dose.

Stacked effect: falls and blood pressure. Amlodipine, metoprolol and the orthostatic drop combine with tramadol's sedation and dizziness. The fall is the result the list predicted.

Opposing effects: cognition. Donepezil raises acetylcholine to support cognition; oxybutynin blocks acetylcholine and is strongly anticholinergic. The two work against each other, and oxybutynin can worsen confusion in a patient with dementia (American Geriatrics Society Beers Criteria Update Expert Panel, 2023).

Stacked effect: serotonin and seizures. Tramadol and sertraline both raise serotonin, and sertraline inhibits the metabolism of tramadol to its active form while tramadol lowers the seizure threshold. The combination carries a risk of serotonin syndrome.

Stacked effect: bleeding. Warfarin with an elevated INR, sertraline (which impairs platelet function) and a history of peptic ulcer raise bleeding risk, especially after a fall.

Real Against Theoretical

Not every pairing deserves action. Amiodarone and metoprolol both slow the heart rate, but the patient's resting rate is 64 and stable, so this pairing is watched rather than changed. Omeprazole and warfarin interact modestly through CYP2C19; in practice, the effect on INR is small. The pairings that matter most today are those connected to the fall, the high INR and the cognitive decline.

Subtraction Counts as Prescribing

Four medicines come off or come down, each with a reason.

Oxybutynin: stop. It is strongly anticholinergic, opposes donepezil and is on the Beers list to avoid in older adults, particularly those with dementia (American Geriatrics Society Beers Criteria Update Expert Panel, 2023). Urgency will be managed first with timed voiding and fluid timing; if medication is still needed, mirabegron is an option without anticholinergic effects, with a blood pressure check.

Tramadol: taper and stop. It contributes to dizziness and falls and interacts with sertraline. Because it has been used daily, it is reduced by 50 mg every three to four days to avoid withdrawal, while scheduled acetaminophen 650 mg every six hours, maximum 3 g daily, and topical diclofenac gel to both knees take over for osteoarthritis pain.

Simvastatin: reduce, then switch. At 40 mg with amiodarone it exceeds the labeled limit. It is changed to pravastatin 40 mg at bedtime, which is not metabolized by CYP3A4.

Omeprazole: step down. Eight years of therapy without a current indication carries risks including fracture and Clostridioides difficile infection (American Geriatrics Society Beers Criteria Update Expert Panel, 2023). Because the patient has a past ulcer and now takes warfarin with sertraline, stopping completely is not appropriate; the dose is reduced to 20 mg daily rather than stopped.

Adjustments That Stay

Warfarin: hold tonight's dose and reduce the weekly total by about 15%, rechecking the INR in five to seven days, because amiodarone is likely to keep the INR high. A direct oral anticoagulant could be considered later (Joglar et al., 2024), but the decision is postponed until the list is stable and the patient's renal function and costs are reviewed.

Amlodipine: reduce from 10 mg to 5 mg, given the orthostatic drop, with home pressure readings.

Docusate: stop, since it adds little; replace with polyethylene glycol 17 g daily for constipation.

What the Changes Should Achieve

The changes are linked to measurable aims. Stopping tramadol and oxybutynin and reducing amlodipine should lower the orthostatic drop and the dizziness that preceded the fall; the target is a standing systolic pressure within 20 mm Hg of the lying value and no dizziness on standing at the two-week visit. Holding and reducing warfarin should bring the INR back into the 2.0 to 3.0 range within one to two weeks. Removing the anticholinergic should not worsen urinary urgency enough to cause incontinence, which the daughter will record on a simple diary. The pravastatin switch should remove the myopathy risk without loss of lipid control, checked at the next routine lipid panel. If knee pain becomes worse after tramadol is stopped, the dose of acetaminophen is not raised beyond 3 g daily; physical therapy and an intra-articular injection are the next options.

An Agent Chosen for What It Avoids

Where something new is added, it is chosen for what it does not do. Acetaminophen and topical diclofenac relieve knee pain without sedation, serotonergic effects or significant bleeding risk from systemic absorption. Polyethylene glycol relieves constipation without electrolyte disturbance. Pravastatin keeps lipid lowering without the amiodarone interaction.

Follow-Up

INR in five to seven days and weekly until stable. A clinic visit in two weeks to check orthostatic pressures, knee pain, urinary symptoms and any withdrawal symptoms from the tramadol taper. Liver enzymes and thyroid function, both of which amiodarone can disturb, at the next scheduled interval, with a chest radiograph if new cough develops. A medication list printed in large type for the patient's daughter, with the stopped medicines crossed out and the bottles taken back to the pharmacy. Deprescribing in older adults works best as a structured process that reviews each drug against current goals and stops one at a time where possible (Scott et al., 2015), and as a conversation about goals, and the patient's goal here is to stay at home and avoid another fall.

References

American Geriatrics Society Beers Criteria Update Expert Panel. (2023). American Geriatrics Society 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society, 71(7), 2052-2081. https://doi.org/10.1111/jgs.18372

Joglar, J. A., Chung, M. K., Armbruster, A. L., Benjamin, E. J., Chyou, J. Y., Cronin, E. M., Deswal, A., Eckhardt, L. L., Goldberger, Z. D., Gopinathannair, R., Gorenek, B., Hess, P. L., Hlatky, M., Hogan, G., Ibeh, C., Indik, J. H., Kido, K., Kusumoto, F., Link, M. S., . . . Van Wagoner, D. R. (2024). 2023 ACC/AHA/ACCP/HRS guideline for the diagnosis and management of atrial fibrillation: A report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation, 149(1), e1-e156. https://doi.org/10.1161/CIR.0000000000001193

Scott, I. A., Hilmer, S. N., Reeve, E., Potter, K., Le Couteur, D., Rigby, D., Gnjidic, D., Del Mar, C. B., Roughead, E. E., Page, A., Jansen, J., & Martin, J. H. (2015). Reducing inappropriate polypharmacy: The process of deprescribing. JAMA Internal Medicine, 175(5), 827-834. https://doi.org/10.1001/jamainternmed.2015.0324