Study on the Adverse Drug Reactions and Drug-Drug Interactions in Elderly Polypharmacy Patients
DOI:
https://doi.org/10.52783/jns.v14.3248Keywords:
Adverse Drug Reactions, Drug-Drug Interactions, Polypharmacy, Elderly Patients, Medication SafetyAbstract
Aim: This study aims to evaluate the prevalence, severity, and clinical impact of adverse drug reactions (ADRs) and drug-drug interactions (DDIs) in elderly patients receiving polypharmacy (≥5 medications). It also seeks to identify the most commonly implicated drug classes and assess the association between polypharmacy, comorbidities, and medication-related complications.
Materials and Methods: A prospective observational study was conducted at a tertiary care hospital, including 100 elderly patients (≥65 years) on multiple medications. Data on demographics, comorbidities, medication history, ADRs, and DDIs were collected using a structured format. ADRs were assessed for causality (Naranjo Scale), severity (Hartwig and Siegel Scale), and preventability (Schumock and Thornton criteria). DDIs were identified and classified based on their clinical significance using standard drug interaction databases. Statistical analysis was performed using SPSS 25.0, with significance set at p < 0.05.
Results: The mean age of the patients was 72.5 ± 5.8 years, with 55% males and 45% females. The average number of comorbidities was 3.2 ± 1.5, with hypertension (65%), diabetes mellitus (50%), and ischemic heart disease (25%) being the most prevalent. Polypharmacy was observed in all patients, with 40% taking 5-6 medications, 30% on 7-8, and 10% on more than 10 drugs. ADRs were recorded in 50% of patients, with 40% classified as probable and 20% as definite ADRs. Severe ADRs were noted in 20% of cases (p=0.01). Moderate-to-severe DDIs were identified in 75% of patients, leading to hospitalization in 15% of cases (p=0.02) and medication changes in 40% (p=0.03). The most implicated drug classes in ADRs and DDIs included antihypertensives (30% ADRs, 25% DDIs), antidiabetics (25% ADRs, 20% DDIs), NSAIDs (15% ADRs, 30% DDIs), and anticoagulants (20% ADRs, 35% DDIs, p=0.005).
Conclusion: This study highlights the high prevalence of ADRs and DDIs in elderly polypharmacy patients, with moderate-to-severe ADRs affecting 50% of patients and hospitalization occurring in 15% of DDI cases. Polypharmacy significantly increased the risk of ADRs and DDIs, particularly with high-risk medications such as antihypertensives, anticoagulants, NSAIDs, and antidiabetics. The findings emphasize the need for regular medication reviews, deprescribing strategies, and improved pharmacovigilance to minimize medication-related harm in geriatric patients
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Davies LE, Spiers G, Kingston A, Todd A, Adamson J, Hanratty B. Adverse outcomes of polypharmacy in older people: systematic review of reviews. J Am Med Dir Assoc. 2020 Feb;21(2):181-187.
Insani WN, Whittlesea C, Alwafi H, Man KKC, Chapman S, Wei L. Adverse drug reactions and associated patient characteristics in primary care. Br J Gen Pract. 2023 Mar;73(728):e211-e218.
Narayan S, Blyth FM, McLachlan AJ, Naganathan V, Hilmer SN. Antidepressants for the treatment of chronic pain in older adults: a systematic review and meta-analysis. Age Ageing. 2024 Jan;53(1):afad123.
Marcum ZA, Perera S, Thorpe JM, Switzer GE, Castle NG, Strotmeyer ES, et al. Anticholinergic use and recurrent falls in community-dwelling older adults: findings from the Health ABC Study. Ann Pharmacother. 2021 Jul;55(7):817-824.
Nobili A, Licata G, Salerno F, Pasina L, Tettamanti M, Franchi C, et al. Polypharmacy, length of hospital stay, and in-hospital mortality among elderly patients in internal medicine wards: The REPOSI study. Eur J Clin Pharmacol. 2011;67(5):507-19.
Onder G, Petrovic M, Tangiisuran B, Meinardi MC, Markito-Notenboom W, Somers A, et al. Development and validation of a score to assess risk of adverse drug reactions among in-hospital patients aged 65 years and older: The GerontoNet ADR risk score. Arch Intern Med. 2013;173(17):1629-36.
Hanlon JT, Wang X, Handler SM, Pugh MJ, Semla TP, Weisbord SD, et al. Potentially inappropriate medication use and risk of adverse drug reactions in older adults. J Am Geriatr Soc. 2014;62(6):1120-5.
Aparasu RR, Mort JR. Inappropriate prescribing for the elderly: Beers criteria-based review. Ann Pharmacother. 2017;34(3):338-46.
Taché SV, Sönnichsen A, Ashcroft D. Prevalence of adverse drug events in ambulatory care: A systematic review. Ann Pharmacother. 2011;45(7-8):977-89.
Kennedy J, Luo Q. Herbal medicine use and potential adverse drug interactions in older adults. J Am Geriatr Soc. 2018;66(5):1000-6.
Björkman IK, Fastbom J, Schmidt IK, Bernsten CB. Drug–drug interactions in the elderly. Ann Pharmacother. 2018;36(11):1675-81.
Maher RL, Hanlon J, Hajjar ER. Clinical consequences of polypharmacy in elderly. Expert Opin Drug Saf. 2014;13(1):57-65.
Hajjar ER, Cafiero AC, Hanlon JT. Polypharmacy in elderly patients. Am J GeriatrPharmacother. 2013;5(4):345-51.
Routledge PA, O’Mahony MS, Woodhouse KW. Adverse drug reactions in elderly patients. Br J Clin Pharmacol. 2010;57(2):121-6.
Gupta M, Malhotra S, Jain S, Dhawan D. Drug interactions in geriatric patients: Pharmacokinetic and pharmacodynamic considerations. J Geriatr Med. 2019;8(2):45-52.
Guthrie B, Makubate B, Hernandez-Santiago V, Dreischulte T. The rising tide of polypharmacy and drug-drug interactions: Population database analysis 1995–2010. BMC Med. 2015;13:74.
Secoli SR, Figueras A, Lebrão ML, De Lima FD, Santos JL. Risk of potential drug-drug interactions among Brazilian elderly: A population-based study. Pharmacoepidemiol Drug Saf. 2017;19(9):858-65.
Alhawassi TM, Krass I, Bajorek BV, Pont LG. A systematic review of the prevalence and risk factors for adverse drug reactions in elderly patients. J Clin Pharm Ther. 2019;44(1):1-21.
Marcum ZA, Amuan ME, Hanlon JT, Aspinall SL, Pugh MJ. Prevalence of potentially inappropriate medication prescribing and polypharmacy among older adults across care settings. Drugs Aging. 2016;33(12):1015-25.
Passarelli MC, Jacob-Filho W, Figueras A. Adverse drug reactions in an elderly hospitalised population: Inappropriate prescription is a leading cause. Drugs Aging. 2012;22(9):767-77.
Wooten JM, Galavis JM, Freeman JK. Drug-induced geriatric syndromes: Focus on falls and delirium in hospitalized patients. J Pharm Pract. 2013;26(5):488-99.
Davies EA, O’Mahony MS. Adverse drug reactions in special populations: The elderly. Br J Clin Pharmacol. 2016;80(4):796-807.
Tangiisuran B, Scutt G, Stevenson J, Wright J, Howard R, Rajkumar C. Adverse drug reactions in elderly hospitalized patients: A prospective study. Drugs Aging. 2012;29(8):669-79.
Budnitz DS, Lovegrove MC, Shehab N, Richards CL. Emergency hospitalizations for adverse drug events in older Americans. N Engl J Med. 2011;365(21):2002-12.
Pirmohamed M, James S, Meakin S, Green C, Scott AK, Walley TJ, et al. Adverse drug reactions as cause of admission to hospital: Prospective analysis of 18,820 patients. BMJ. 2004;329(7456):15-9
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