Drug-induced falls

Falls represent a common and complex geriatric pathology profile.1 About 30% of elderly patients living in community fall at least once per year and half of them has frequent falls.1-2
Percentages are higher for more advanced age group and for institutionalised subjects.3 Falls and their complications are one of the principal causes of death among elderly, besides they can lead to functional decline, hospitalization, institutionalisation and high healthcare costs.3-4 Identification and correction of risk factors can significantly reduce the risk of future falls.3 In spite of this evidence, falls prevention has been largely neglected in clinical practice.5
Falls risk is multifactorial and is linked to intrinsic and extrinsic factors in the elderly.1
Many commonly used drugs are significantly correlated to falls in elderly patients and are one of the most important risk extrinsic factor.1-5 Pharmacokinetics and pharmacodynamics properties of drugs change with aging.4 In elderly patients the increase of total fat mass causes the prolongation of lipophilic drugs half-life; in fragile and malnourished elderly, serum albumin is often reduced, therefore increasing the free drugs fraction; hepatic and renal functionality alterations can also modify drug actions. All these factors, associated to comorbidity, polypharmacotherapy and increase of inappropriate prescriptions make elderly patients more subject to adverse drug reactions, falls included.4
Several studies evaluated the association between specific drugs or drugs classes and the probability of falls. A wide meta-analysis of studies conducted between 1966 and 1996 was published in 1999.6 Since then, new studies have been published as an update. The acronym FRID (Fall Risk Increasing Drugs) has been used for the first time by Van der Velde identifying a list of drugs associated to falls.7 The most prescribed FRIDs are cardiovascular drugs, benzodiazepine, antidepressant, antiepileptic, antipsychotics, antiparkinsonian and opiate drugs (see Table 1).5 A systemic review8 published in April 2013 identifies 156 risk-factors associated to falls in patients aged 60 years and over: 13 factors are extrinsic, 32 factors are iatrogenic, 57 factors are linked to clinical history, 29 factors are relative to patients physical characteristics and the last 25 factors are linked to socio-demographic characteristics. Table 1 shows the odds ratio for iatrogenic factors.8 Falls risk reduction in elderly patients (and their consequent lesions) undoubtedly requires actions on several fronts, however drugs are one of the most easily modifiable risk factors.5,9
A study conducted in 1994 has already showed that reducing the number of drugs to four or less is one of the most effective strategies for reducing the risk of falls in elderly patients living in community.10
For what concerns inappropriate prescriptions, very common in elderly patients,11 it is interesting to notice that two of the most used screening instruments – Beers criteria and STOPP & START – both dedicated a special section to drugs implicated in falls, advising the careful evaluation of their discontinuation.12,13

Table 1 – Odds ratio for falls by iatrogenic risk factors