Defending a Stroke Prevention Regimen in a 74 Year Old With Nonvalvular Atrial Fibrillation, Stage 3b Chronic Kidney Disease and Nine Medications
[Student Name]
Edson College of Nursing and Health Innovation, Arizona State University
DNP 608: Advanced Pharmacotherapeutics Across the Lifespan
Dr. [Course Faculty]
October 13, 2025
Model document. The patient is a composite; no part of this paper is clinical guidance.
The Patient, the Risk Estimates and the Medication List
Atrial fibrillation becomes common with age, and in patients 65 years and older stroke prevention is the single decision that changes outcomes most (Joglar et al., 2024). The patient described here is a composite built for teaching and represents no real person. She is a 74 year old woman whose 14 day ambulatory patch monitor, ordered for three months of palpitations, recorded atrial fibrillation across 31 percent of the recording with resting ventricular rates of 96-118. She weighs 58 kg, stands 160 cm, and carries diagnoses of hypertension, type 2 diabetes, knee osteoarthritis, gastroesophageal reflux and chronic insomnia. She lives alone, drives, and reports two falls in the past year without injury.
Serum creatinine was 1.4 mg/dL. Estimated glomerular filtration rate by the 2021 CKD EPI equation was 38 mL/min/1.73 m2, while creatinine clearance by the Cockcroft Gault equation, which is the estimate anticoagulant labeling actually uses, was 32 mL/min. Hemoglobin was 11.8 g/dL, platelets 210,000/mm3, albumin 3.8 g/dL, and transaminases were normal. Her CHA2DS2 VASc score is 4, from age 65-74, female sex, hypertension and diabetes, a score associated with an untreated stroke rate of roughly 4 percent per year. HAS BLED is 4, driven by hypertension, renal impairment, age above 65 and concurrent antiplatelet and anti-inflammatory use.
Her list holds nine medications: lisinopril 20 mg daily, metformin 1,000 mg twice daily, atorvastatin 40 mg nightly, aspirin 81 mg daily begun for primary prevention 11 years ago, naproxen 220 mg twice daily bought over the counter for knee pain, omeprazole 20 mg daily continued since a course for reflux six years ago, zolpidem 10 mg nightly for two years, calcium carbonate with vitamin D, and diltiazem extended release 180 mg daily added by a covering clinician for rate control. A high HAS BLED score in this case identifies modifiable hazards inside that list rather than a reason to withhold anticoagulation, and three of the nine medications are the hazards it is counting.
Selecting the Agent and Defending the Dose
The regimen argued for in this paper is apixaban 5 mg twice daily, metoprolol succinate 50 mg daily in place of diltiazem, and metformin reduced to 500 mg twice daily, with every line of reasoning below tied to this composite patient rather than offered as direction to a reader. Direct oral anticoagulants are preferred over warfarin in nonvalvular atrial fibrillation for patients without moderate to severe mitral stenosis or a mechanical valve (Joglar et al., 2024). Renal handling then separates the four agents at a creatinine clearance of 32 mL/min: rivaroxaban requires a reduced daily dose below 50 mL/min, dabigatran is roughly 80 percent renally cleared, and edoxaban carries an upper clearance boundary as well as a lower one.
The dose is where this case is most often mishandled. United States labeling reduces apixaban to 2.5 mg twice daily only when two of three conditions are present: age 80 years or older, body weight 60 kg or less, and serum creatinine 1.5 mg/dL or greater. This patient meets exactly one of them, her weight of 58 kg, so the labeled dose is the full one, and a clearance of 32 mL/min does not by itself trigger a reduction. The reflex to reduce anyway is not harmless. In a national registry of patients treated with these agents, dosing that departed from labeling was associated with higher all cause mortality and no reduction in bleeding (Steinberg et al., 2016).
The efficacy evidence supports the choice at that dose. In ARISTOTLE, 18,201 patients with atrial fibrillation and at least one additional risk factor received apixaban or warfarin, and apixaban reduced stroke or systemic embolism by 21 percent, major bleeding by 31 percent and hemorrhagic stroke by roughly half, with all cause mortality also lower (Granger et al., 2011). Rate control moves to metoprolol succinate because diltiazem inhibits both cytochrome P450 3A4 and P glycoprotein, the two pathways that clear apixaban, and because a negative inotrope earns less place here than a beta blocker. Metformin continues at 1,000 mg total per day, the ceiling labeling sets between filtration rates of 30 and 45 mL/min/1.73 m2.
Interaction Screening and What Comes Off the List
Interaction screening runs against the new agent and the old list together. Naproxen is the first hazard, since nonsteroidal anti-inflammatory drugs roughly double the risk of major bleeding when combined with an oral anticoagulant, and in a patient already taking an angiotensin converting enzyme inhibitor at a clearance of 32 mL/min the same drug threatens the kidney through afferent arteriolar constriction. The 2023 Beers criteria name chronic nonsteroidal use in adults 65 years and older, and the pairing of a nonsteroidal with an anticoagulant, as potentially inappropriate (American Geriatrics Society Beers Criteria Update Expert Panel, 2023). The plan for this composite patient substitutes topical diclofenac, scheduled acetaminophen and a physical therapy referral for knee strengthening.
Aspirin is the second. It was begun for primary prevention, an indication the U.S. Preventive Services Task Force no longer supports for initiation at age 60 years or older, and adding an antiplatelet to an anticoagulant without an acute coronary or recent stent indication raises bleeding without lowering ischemic events (U.S. Preventive Services Task Force, 2022). It ends on the day the anticoagulant begins. Zolpidem is the third, since benzodiazepine receptor agonists carry a Beers recommendation to avoid in older adults, and their harm here is indirect: sedation and nocturnal unsteadiness produce the falls that make an anticoagulated intracranial bleed possible. It tapers across three months alongside cognitive behavioral therapy for insomnia.
Two interactions call for judgment rather than removal. Diltiazem inhibits 3A4 and P glycoprotein moderately and raises apixaban exposure by roughly 40 percent, which labeling does not treat as a dose changing interaction, since only strong dual inhibitors such as ketoconazole, itraconazole, ritonavir and clarithromycin carry that instruction. Substituting a beta blocker retires the question without a calculation. Omeprazole runs the other way. Beers flags proton pump inhibitors continued past two months without a documented indication, yet in an anticoagulated patient with prior nonsteroidal exposure and a hemoglobin of 11.8 g/dL, gastroprotection has become the indication. Deprescribing is not subtraction, and the drug that looks least defensible on a list is not always the one that leaves it.
Monitoring Parameters and the Criteria for Stopping
Monitoring for this regimen is scheduled rather than incidental. Renal function is rechecked at three months and then at an interval given by the clearance divided by ten in months, which at 32 mL/min returns roughly quarterly, and sooner during any acute illness that lowers volume. A complete blood count follows the same calendar, because a baseline hemoglobin of 11.8 g/dL leaves little margin before occult blood loss becomes visible. Routine coagulation testing has no place here: prothrombin time and activated partial thromboplastin time do not track apixaban effect, and a chromogenic anti factor Xa assay calibrated to the drug belongs only to bleeding, urgent surgery or suspected accumulation. Blood pressure under 130/80 mm Hg, adherence, falls since the last visit and hemoglobin A1C complete the set.
Stopping criteria are written in advance so the decision is not improvised during an emergency by whoever is present. Interruption before a procedure is temporary and scales with the bleeding risk of the procedure and with clearance, and the drug resumes once hemostasis allows. Permanent discontinuation is reserved for a life threatening bleed without a reversible source, an intracranial bleed, a documented change to comfort focused goals, or the patient's informed preference after the tradeoff has been discussed. Falls alone do not qualify, and the arithmetic is worth carrying: a decision analysis estimated that a patient would need to fall roughly 295 times in one year before the risk of subdural bleeding outweighed the benefit of stroke prevention (Man-Son-Hing et al., 1999). In this case the answer to falls is to remove the sedative rather than the anticoagulant.
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.
Granger, C. B., Alexander, J. H., McMurray, J. J. V., Lopes, R. D., Hylek, E. M., Hanna, M., Al-Khalidi, H. R., Ansell, J., Atar, D., Avezum, A., Bahit, M. C., Diaz, R., Easton, J. D., Ezekowitz, J. A., Flaker, G., Garcia, D., Geraldes, M., Gersh, B. J., Golitsyn, S., ... Wallentin, L. (2011). Apixaban versus warfarin in patients with atrial fibrillation. New England Journal of Medicine, 365(11), 981-992. https://doi.org/10.1056/NEJMoa1107039
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. Circulation, 149(1), e1-e156.
Man-Son-Hing, M., Nichol, G., Lau, A., & Laupacis, A. (1999). Choosing antithrombotic therapy for elderly patients with atrial fibrillation who are at risk for falls. Archives of Internal Medicine, 159(7), 677-685.
Steinberg, B. A., Shrader, P., Thomas, L., Ansell, J., Fonarow, G. C., Gersh, B. J., Kowey, P. R., Mahaffey, K. W., Naccarelli, G., Reiffel, J., Singer, D. E., Peterson, E. D., & Piccini, J. P. (2016). Off-label dosing of non-vitamin K antagonist oral anticoagulants and adverse outcomes: The ORBIT-AF II registry. Journal of the American College of Cardiology, 68(24), 2597-2604.
U.S. Preventive Services Task Force. (2022). Aspirin use to prevent cardiovascular disease: Preventive medication. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/aspirin-to-prevent-cardiovascular-disease-preventive-medication
How this DNP 608 Module 5 example is structured
Arizona State University publishes no module by module deliverable names for Advanced Pharmacotherapeutics Across the Lifespan, so this DNP 608 Module 5 example is written as the genre the module almost certainly wants: in many sections this module asks for a drug therapy plan defended for a single patient, and your course instructions and rubric decide the exact form. The first sheet gives the patient, the risk estimates and the whole medication list, because a regimen cannot be defended against a list that has not been shown. The second sheet selects the agent and argues the dose against labeling criteria and trial evidence. The third sheet screens interactions and says what leaves the list and what stays. The last sheet sets monitoring parameters and the conditions under which the drug is stopped. Nothing here is clinical guidance; the patient is a composite.
DNP 608 Module 5 questions, answered
What does DNP 608 Module 5 usually ask for?
Arizona State University does not publish module by module deliverable names for this course, so aim at the genre. In many sections this module asks for a pharmacotherapy plan for one patient, defended with dosing rationale, monitoring parameters, interaction screening and criteria for stopping. Your course instructions and rubric decide the exact form, the headings and how many references are expected.
How much dosing detail belongs in a doctoral pharmacotherapy paper?
Enough to show the reasoning, which means the labeled criteria, the patient values you compared them against, and the pharmacokinetic reason those values matter. A paper that states a dose without naming the clearance, the weight and the interaction pathways behind it has described a prescription rather than defended one. Papers written for coursework are model documents, not directions for care.
Do I have to include deprescribing?
If the case involves an older adult on several medications, yes in practice, because the regimen you add is only as safe as the list it joins. Strong papers name the criteria set they applied, say what leaves the list and what replaces it, and defend at least one medication they chose to keep despite a flag against it.
Write yours, or have the desk draft it
This paper is an original model document written by our desk, not a submitted student paper and not an official Arizona State University document. Read it for the moves, then write your own to the instructions in your classroom. If you want one built to your exact prompt and rubric, the first custom sample is free and arrives in 24 to 48 hours.