Adverse Drug Reactions in Older People: A Twenty-First Century View

Adverse drug reactions (ADRs) represent a growing threat to the safety and welfare of older people in all care settings. The risk of an older person experiencing a clinically serious ADR is determined by several key factors, principally exposure to polypharmacy, degree of frailty, concurrent impairment of major organ function and the presence of inappropriate medications. ADRs in older people are considered a public health problem, given the increasing numbers of people in the general population who experience ADRs due the current demographic shifts towards ageing in most countries. ADRs are also highly costly, accounting for approximately 10% of all acute unselected hospitalisations in older people, compared to approximately 6% in the general adult population. ADRs are mostly predictable and, therefore, preventable. Scrutiny of older patients’ medications, particularly at points of care transition, using validated assessment tools for detection of inappropriate medications can help to minimise the prevalence of ADRs. All clinical staff dealing with older patients should be aware that ADRs often present with non-specific symptoms such as confusion, poor appetite, lethargy, altered bowel habit and falls that can be easily but erroneously ascribed to new age-related symptoms; this is a particular risk in the oldest and frailest patients. Clinicians should, therefore, always consider that new symptoms could result from ADRs and should maintain a high degree of suspicion of an iatrogenic basis for new symptoms, particularly if symptoms coincide with the introduction of new medication.