Medication-Related Dizziness in the Older Adult

With increased medication use among the older adult population, adverse drug events and polypharmacy can be significant causes of dizziness in the elderly. The evidence evaluated in this review is helpful in clinical practice but requires an additional detailed investigation into the agents discussed to understand the risk/benefit ratio associated with medications. Examples of medications highly associated with dizziness in older adults and discussed in this review include cardiovascular and central nervous system agents. Several other medication classes associated with dizziness are among the medications most commonly used by older patients.

Key points

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Dizziness is highly prevalent among patients aged 65 years and older and is associated with multiple risk factors such as comorbid diseases and medications.
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The consequences of dizziness affect patients’ health and quality of life and create an enormous economic burden on the health care system.
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For physicians to manage dizziness appropriately in older adults, it is crucial to assess the possible underlying causes of dizziness that will facilitate accurate clinical decision making.
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Performing a medication history and review are important for adjusting the medication regimen to help prevent or resolve medication-related dizziness.

Mrs K. J. is a pleasant, articulate 79-year-old woman describing episodic vertigo and chronic lightheadedness that began approximately 2 years ago without any antecedent illness or injury. She states that the vertigo occurs without warning, lasting 15 to 30 minutes at each occurrence, and resolves completely with no residual symptoms. She has noted tightness in her chest, numbness and tingling in her lips and hands, grayed vision, and clammy sweating during these episodes. She denies associated auditory symptoms. She reports that she had 4 such episodes in the past year. Her symptoms of lightheadedness occur daily and seem slightly worse on transitioning from supine to sitting or sitting to standing position. She feels reasonably well when she first begins her morning routine but reports a foggy, disconnected feeling by midmorning, which persists until evening before gradually improving. She denies falls but reports near-falls 2 to 3 times per week. She lives alone following the death of her husband last year and becomes tearful and slightly agitated when expressing concerns for her own future in light of these symptoms. Her medical history is significant for hypertension, peripheral neuropathy affecting her legs below the knee, depression, anxiety, and seasonal allergies. Her medication list includes hydrochlorothiazide, propranolol, diazepam, meclizine, calcium and vitamin D supplements, fish oil, and garlic tablets.

Medication-related dizziness

Dizziness is highly prevalent among adults aged 65 years and older in primary care or family practice settings, with estimates of greater than 30% in community-dwelling older adults and a higher prevalence in women than men. A study of emergency department (ED) visits (1993–2005) from the National Hospital Ambulatory Medical Care Survey (NHAMCS) is in agreement with these facts from studies conducted in single institutions. From a total of 9472 dizziness cases sampled over this period, the study demonstrated that dizziness is an extremely common ED symptom that preferentially affects older adults and a greater proportion of women. From an epidemiologic standpoint, it can be hypothesized that the incidence of dizziness-associated complications are expected to increase in the future based on the increasing US population projections for persons aged 65 years and older. According to the US Census Bureau, it is projected that 20% of Americans will be aged 65 years and older by 2030, and by 2050, this age group is projected to increase to 88.5 million from 38.7 million in 2008. Similarly, the 85 years and older population is expected to increase to 19 million by 2050 from 5.4 million in 2008.

Although dizziness seems to increase with aging, normal aging is not the cause of dizziness but other factors associated with aging make older adults more susceptible to dizziness. Comorbid conditions, drug-related problems (due in part to altered pharmacokinetics and pharmacodynamics), polypharmacy, larger number of doses of medications per day, low body weight, and a history of adverse drug reactions predispose older adults to dizziness.

Pharmacokinetics describes the relationship between the dose of the drug administered and the resulting drug concentrations achieved in the systemic circulation. Aging is generally characterized by changes in all pharmacokinetic processes including absorption, distribution, metabolism, and excretion, although the most clinically important changes are those affecting hepatic and renal drug elimination. Hepatic metabolism may be reduced in older adults, particularly for drugs metabolized primarily by oxidative pathways. Impaired renal function with aging results in reduced renal clearance for drugs eliminated by the kidneys. Altered pharmacokinetics with aging increases the risk of adverse drug events (ADEs), such as dizziness in older adults.

Pharmacodynamics describes the relationship between drug concentrations in the systemic circulation and drug response. Aging also affects pharmacodynamics through several mechanisms including altered concentrations of the drug at the receptor, altered interactions between the drug and its receptor, and changes in homeostatic regulation. Pharmacodynamic changes often result in increased sensitivity to medications, especially for drugs acting on the central nervous system (CNS). Altered pharmacodynamics can also contribute to increased risk of ADEs, such as dizziness in older adults.

Polypharmacy refers to the use of multiple medications and/or the administration of more medications than is clinically indicated, representing unnecessary drug use. Polypharmacy is associated with higher risk of ADEs, inappropriate use of medications, nonadherence, geriatric syndromes, and mortality in older adults. In addition, ADEs can result from prescriber-related factors such as therapeutic duplication, that is, prescriptions for one patient initiated by more than one prescriber, increasing the risk of uncoordinated care.

There is a wide range of consequences associated with dizziness, and these may significantly affect the quality of life and health care burden. For example, Cigolle and colleagues performed a cross-sectional study to examine the prevalence of geriatric conditions among older adults (eg, dizziness) and the association of these conditions with activities of daily living dependency (eg, cognitive impairment contributing to dependency for bathing and dressing). In this study, data were obtained from the year 2000 from the Health and Retirement Study, a biennial longitudinal health interview survey of a cohort of adults aged 50 years or older in the United States. The results showed a strong and significant association, suggesting that geriatric conditions are associated with disability.

Considerable progress has been made in the clinical setting to describe and define dizziness and its potential causes. Dizziness is a common symptom reported by older patients during physician visits. Dizziness is an obscure multifactorial symptom associated with various diseases affecting the sensory organs, the CNS, or both. It may also be induced by processes outside the CNS or sensory organs, such as cardiovascular diseases, or by medications. Dizziness is a complex and subjective complaint. In fact, difficulty in diagnosing dizziness in older adults in family practice and in specialty practice settings has been reported. The term dizziness can describe many different sensations that can be categorized by subtypes. These subtypes include vertigo, presyncope, disequilibrium, and nonspecific dizziness. In a medical chart audit study, it was recommended that documentation of selected key quality indicators in the management of dizziness could improve clinical diagnosis.

Medication-related dizziness can be difficult to diagnose, especially in older persons, in whom it can masquerade as a geriatric syndrome. Geriatric syndromes are difficult to define, but they are characterized as symptoms with multifactorial causes, which become more common with aging and are in fact often mistaken for normal aging. Shared risk factors may lead to geriatric syndromes. The common geriatric syndromes associated with high degree of morbidity include incontinence, falls, pressure ulcers, delirium, and functional decline. Dizziness is considered by some geriatricians to meet the definition of a geriatric syndrome. ADEs in older patients often present as nonspecific symptoms or geriatric syndrome indicators, such as cognitive impairment or falls. Falls may be related to osteoarthritis, poor visual acuity, and/or prescription medication affecting balance. Discovering the underlying cause may be challenging. Similarly, other health issues associated with dizziness are often multifactorial. Involvement of cardiovascular, neurologic, sensory, and psychological domains, as well as medication-related ADEs suggest that dizziness may be a geriatric syndrome. Results from a cross-sectional study of ED visits for dizziness from the NHAMCS database support these associations. The study showed that the following diagnoses were at least twice as likely among patients presenting with dizziness: otovestibular, cerebrovascular, metabolic, and cardiovascular disorders.

Because dizziness in the elderly may be more serious than in any other age group, accurate diagnosis and appropriate intervention are crucial. The key component in the evaluation and general management of dizziness in older adults is patient history. A complete medication history is considered critical to the evaluation. Similarly, Salles and colleagues suggest that an interdisciplinary treatment approach to minimize contributive causes of dizziness in the elderly is to adjust the medication regimen. Medication history should include prescription medications, over-the-counter medications, herbal medicines, and nutraceuticals, as well as recreational drugs (including smoking and alcohol). Common drug categories implicated in dizziness in older adults are listed in Table 1 .

Table 1

Medications that often cause dizziness in older adults

Class of Medication	Possible Mechanism
α ₁-Adrenergic antagonists	Orthostatic hypotension
Alcohol	Hypotension, osmotic effects
Aminoglycosides	Ototoxicity
Anticonvulsants	Orthostatic hypotension, cerebellar dysfunction
Antidepressants	Orthostatic hypotension
Anti-Parkinson medication	Orthostatic hypotension
Antipsychotics	Orthostatic hypotension
β-Blockers	Hypotension or bradycardia
Calcium channel blockers	Hypotension, vasodilation
Class 1a antiarrhythmics	Torsades de pointes
Digitalis glycosides	Hypotension
Diuretics	Volume contraction, vasodilation
Narcotics	CNS depression, torsades de pointes
Oral sulfonylurea	Hypoglycemia
Vasodilators	Hypotension, vasodilation
Anticoagulants	Bleeding complications
Antidementia agents	Bradycardia, syncope
Antihistamines: sedating	Torsades de pointes
Antirheumatic agents	Vestibular disturbance
Anti-infectives: anti-influenza agents, antifungals (oral), quinolones	Torsades de pointes
Antithyroid agents	Bone marrow toxicity
Anxiolytics	CNS depression
Attention-deficit/hyperactivity disorder agents	Cardiac arrhythmias
Cholesterol-lowering agents	Hypotension
Bronchodilators	Hypotension
Skeletal muscle relaxants	Central anticholinergic effects
Urinary and gastrointestinal antispasmodics	Central anticholinergic effects

Data from Refs.

A recent report examining the epidemiology of central vertigo and dizziness indicated that of the 13 causes of central vertigo reviewed in this study, medication-related dizziness was not considered or discussed in detail. Perhaps, the omission was because of the paucity of the published literature associating medication and dizziness or because medications are simply considered the least consequential factor associated with dizziness. Yet, according to the US Food and Drug Administration (FDA) safety information data contained in the Adverse Event Reporting System (AERS) database, between the years 2004 and 2009, dizziness was reported to be associated with a wide variety of medications. The authors’ preliminary analysis identified more than 70,000 reports. Because AERS reporting is voluntary, it has been suggested that there is a high degree of under-reporting, and thus the actual number of cases of medication-associated dizziness may be even more than in the records document.

In fact, Kroenke and colleagues, in an earlier review on the frequency of various causes of dizziness, generally categorized medication-related causes as other causes, accounting for only 16% of the causes of dizziness. The other causes of dizziness included anemia and metabolic causes (eg, hypoglycemia, hyperglycemia, electrolyte disturbances, thyroid disease). This possible underestimation is not consistent with findings from the most recent cross-sectional diagnostic study describing subtypes of dizziness in older adult patients in a primary care setting assessing the contributory causes of dizziness. In this study, 417 older adult patients in the Netherlands, aged 65 to 95 years, who consult their family physician for persistent dizziness, underwent a comprehensive evaluation by a panel of specialists. It was found that an ADE was considered to be the most common minor contributory cause of dizziness (23%). In contrast to the results from the study by Kroenke and colleagues, the conclusion drawn from this study was that medications are a significant cause of dizziness in some patients.

This article provides an overview of the available literature regarding medication-related dizziness in adults aged 65 years and older.