Adverse drug reactions in special populations – the elderly

Abstract

The International Conference on Harmonization considers older people a ‘special population’, as they differ from younger adults in terms of comorbidity, polypharmacy, pharmacokinetics and greater vulnerability to adverse drug reactions (ADRs). Medical practice is often based on single disease guidelines derived from clinical trials that have not included frail older people or those with multiple morbidities. This presents a challenge caring for older people, as drug doses in trials may not be achievable in real world patients and risks of ADRs are underestimated in clinical trial populations. The majority of ADRs in older people are Type A, potentially avoidable and associated with commonly prescribed medications. Several ADRs are particularly associated with major adverse consequences in the elderly and their reduction is therefore a clinical priority. Falls are strongly associated with benzodiazepines, neuroleptics, antidepressants and antihypertensives. There is good evidence for medication review as part of a multifactorial intervention to reduce falls risk in community dwelling elderly. Multiple medications also contribute to delirium, another multifactorial syndrome resulting in excess mortality particularly in frail older people. Clostridium difficile associated with use of broad spectrum antibiotics mainly affects frail older people and results in prolonged hospital stay with substantial morbidity and mortality. Antipsychotics increase the risk of stroke by more than three‐fold in patients with dementia. Inappropriate prescribing can be reduced by adherence to prescribing guidelines, suitable monitoring and regular medication review. Given the heterogeneity within the older population, providing individualized care is pivotal to preventing ADRs.

Population Pharmacokinetics and Pharmacodynamics of Levofloxacin in Acutely Hospitalized Older Patients with Various Degrees of Renal Function

“…Older patients may be at increased risk of adverse drug reactions (ADRs), mainly because of the pathophysiological changes associated with aging processes and/or of polypharmacy (9). High frequencies of tendinopathy and of tendon ruptures in older patients were associated with aging, impairment of renal function, and corticosteroid coadministration (10,11).…”

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“…33.3% of cases had given additional treatment. [9][10][11][12][13] . Aim of this research was to find out association of risk factors in the development of adverse drug reactions and worsening the conditions.…”

MANAGEMENT OF ENDOCRINE DISEASE: l-Thyroxine replacement therapy in the frail elderly: a challenge in clinical practice

“…Noteworthy, thyroid diseases are among the top 10 most common conditions in multimorbid patients, as reported in a Scottish study of primary care patients (6). Increased multimorbidity in turn leads to increased prescribing in the older population, resulting in a plethora of treatments that potentially interfere with each other and may harm, rather than aid, the patient (7,8). Indeed, polypharmacy, defined as taking at least five drugs, has been consistently demonstrated as a risk factor for both drug interactions and/or adverse events (7,8,9).…”

“…Increased multimorbidity in turn leads to increased prescribing in the older population, resulting in a plethora of treatments that potentially interfere with each other and may harm, rather than aid, the patient (7,8). Indeed, polypharmacy, defined as taking at least five drugs, has been consistently demonstrated as a risk factor for both drug interactions and/or adverse events (7,8,9). Old people differ from younger adults in many socio-demographic characteristics (loss of autonomy, social deprivation, long-term residence in nursing home) and physiologic reserves (disability, frailty) and are more vulnerable to the adverse effects of drugs, because of age-related changes in pharmacodynamics and pharmacokinetics (7,9).…”

“…Indeed, polypharmacy, defined as taking at least five drugs, has been consistently demonstrated as a risk factor for both drug interactions and/or adverse events (7,8,9). Old people differ from younger adults in many socio-demographic characteristics (loss of autonomy, social deprivation, long-term residence in nursing home) and physiologic reserves (disability, frailty) and are more vulnerable to the adverse effects of drugs, because of age-related changes in pharmacodynamics and pharmacokinetics (7,9). For these reasons, current clinical guidelines for most chronic diseases may turn out to be potentially inappropriate for older people, since such guidelines derived from clinical trials that have not included older people or those with multimorbidity and have been mainly focused on separate disease management (10,11).…”