Geriatric Case Report Presenting an Alzheimer’s Disease Patient with Polypharmacy Resulting in Significant Drug-Drug Interaction

Vol. 21 No. 6 (suppl) : 2026 (47-55)

Marwan Saad Azzubaidi Marwan Saad Azzubaidi
Mohd Romzi Abd Rahman Mohd Romzi Abd Rahman
Harmy Mohamed Yusoff Harmy Mohamed Yusoff

Abstract
Polypharmacy in elderly patients often leads to complicated clinical scenarios involving significant drug-drug interactions, particularly among individuals diagnosed with Alzheimer’s disease (AD). This report describes the case of an 80-year-old male with multiple comorbidities, including hypertension, type 2 diabetes mellitus, chronic heart failure, osteoarthritis and benign prostatic hyperplasia, who presented with progressive cognitive decline characteristic of AD. Initial evaluation revealed impaired memory, apraxia, mild expressive aphasia and executive dysfunction, alongside notable generalised cortical atrophy and hippocampal volume loss on brain magnetic resonance imaging. The patient was initiated on symptomatic therapy with donepezil, an acetylcholinesterase (AChE) inhibitor, leading to a significant drug-drug interaction with the patient’s long-term beta-blocker, metoprolol, causing symptomatic bradycardia manifested as dizziness, fatigue, worsening confusion and near-syncope. Therefore, metoprolol was discontinued, but the patient subsequently developed poorly controlled hypertension (150/95 mmHg). To optimise blood pressure control while minimising medication burden, the treating physician replaced tamsulosin with doxazosin, effectively managing both hypertension and benign prostatic hyperplasia symptoms. Following these adjustments, the patient’s blood pressure and heart rate normalised, and cognitive symptoms stabilised. This case highlights the clinical complexity inherent in managing elderly patients with multiple chronic conditions and polypharmacy. It underscores the importance of vigilant monitoring and strategic medication selection to avoid drug-drug interactions, particularly when prescribing cognitive enhancers such as donepezil. Careful consideration of individual patient profiles and continuous reassessment of medication regimens remain crucial for enhancing clinical outcomes and patient safety.
Keywords : Alzheimer’s disease; bradycardia; donepezil, drug-drug interaction; hypertension; polypharmacy,
Abstrak
Polifarmasi dalam kalangan pesakit warga emas sering membawa kepada situasi klinikal yang rumit, terutamanya apabila melibatkan interaksi ubat-ubatan yang signifikan dalam pesakit yang didiagnosis dengan penyakit Alzheimer (AD). Laporan ini membincangkan kes seorang lelaki berusia 80 tahun yang menghidap pelbagai komorbiditi termasuk hipertensi, diabetes mellitus jenis 2, kegagalan jantung kronik, osteoartritis dan hiperplasia prostat benign, yang hadir dengan kemerosotan kognitif progresif yang menunjukkan ciri-ciri AD. Penilaian awal menunjukkan gangguan ingatan, apraksia, afasia ekspresif ringan dan disfungsi eksekutif, serta atrofi kortikal umum dan kehilangan isipadu hippocampus yang ketara berdasarkan pengimejan resonans magnetik otak. Pesakit telah dimulakan dengan terapi simptomatik menggunakan donepezil, iaitu perencat asetilkolinesterase, yang membawa kepada interaksi ubat yang signifikan dengan beta-blocker jangka panjang yang diambil oleh pesakit, metoprolol, menyebabkan bradikardia simptomatik yang ditunjukkan melalui pening, keletihan, kekeliruan yang semakin teruk dan hampir pengsan. Oleh itu, metoprolol telah dihentikan, namun pesakit kemudiannya mengalami hipertensi yang tidak terkawal (150/95 mmHg). Bagi mengoptimumkan kawalan tekanan darah sambil mengurangkan beban ubat-ubatan, doktor yang merawat telah menggantikan tamsulosin dengan doxazosin, yang berjaya mengawal kedua-dua simptom hipertensi dan hiperplasia prostat benign. Selepas pelarasan ini, tekanan darah dan kadar nadi pesakit kembali normal dan simptom kognitif menjadi stabil. Kes ini menekankan kerumitan klinikal dalam pengurusan pesakit warga emas dengan pelbagai penyakit kronik dan polifarmasi. Ia juga menegaskan kepentingan pemantauan rapi dan pemilihan ubat secara strategik untuk mengelakkan interaksi ubat-ubatan, khususnya apabila menetapkan ubat penambah kognitif seperti donepezil. Pertimbangan teliti terhadap profil individu pesakit dan penilaian semula berterusan terhadap rejimen ubat adalah penting dalam meningkatkan hasil klinikal dan keselamatan pesakit.
Kata Kunci : Bradikardia; donepezil; hipertensi; interaksi ubat-ubatan; penyakit Alzheimer; polifarmasi,

Correspondance Address
Correspondence: mazzubaidi@gmail.com; mazzubaidi@unisza.edu.my


Non-contrast MRI of the patient’s brain showing generalised cortical atrophy (yellow arrows) and loss of hippocampal volume (red arrows) in (A) FLAIR image and (B) Coronal T1 image of the patient’s brain. These structural changes were consistent with neurodegenerative patterns observed in Alzheimer's disease.