Dizziness

Dizziness is one of the most common symptoms encountered in primary care and among the most common reasons for an emergency department visit, yet it remains genuinely challenging to work up efficiently — the word is nonspecific, and different patients (and the same patient on different days) use it to describe genuinely different sensations. A Canadian chart-audit study at a Toronto family practice clinic notes that dizziness affects over 30% of people aged 65 and older, and found that documentation of the basic quality indicators needed to work it up properly — the patient's own description of the sensation, a current medication list, orthostatic blood pressure measurement, a falls history, and screening for depression — was frequently incomplete in routine practice.^[1] That documented practice gap is exactly where a pharmacist's structured medication review adds the most value.

This chapter is deliberately scoped to the general, pharmacist-relevant medication-induced and multifactorial dizziness workup — the classification framework, the mechanism-based medication differential, the structured review process, and falls-prevention counselling that apply across causes. It does not cover the specific mechanism and treatment of benign paroxysmal positional vertigo (BPPV), which has its own dedicated chapter covering canalithiasis, the Dix-Hallpike test, and the Epley/Semont repositioning maneuvers — cross-reference that chapter whenever the history and bedside testing point specifically to BPPV.

Four categories, and an important caveat about them

Since 1972, dizziness has traditionally been divided into 4 categories based on the patient's own description of the sensation — a framework still worth knowing as a starting vocabulary for organizing the differential:^[2]

The framework's own modern restatement is honest about its limits: the distinction patients draw between these categories is often unreliable in practice, since many cannot cleanly separate "spinning" from "light-headed," and the same patient may describe genuinely different sensations differently on different visits.^[3] A newer, complementary approach — TiTrATE (Timing, Triggers, a Targeted Exam) — classifies dizziness instead by its temporal pattern (episodic vs. continuous) and its triggers (positional, orthostatic, spontaneous), mapping more directly onto an actionable diagnostic pathway and increasingly preferred for acute presentations.^[4] In practice the two frameworks work well together: symptom quality is a reasonable starting point for organizing the differential, and timing/triggers refine it once a category is suspected — both are used throughout this chapter.

Presentation by category

The medication-induced dizziness differential, organized by mechanism

This is the differential most directly actionable by a pharmacist. 4 mechanisms account for the great majority of medication-induced dizziness, and a single patient — particularly an older adult on multiple drugs — can have more than 1 operating at once.

Polypharmacy — the cumulative risk that outweighs any single drug

Even without 1 obvious culprit, the sheer number of medications independently raises dizziness and fall risk. A Canadian systematic review of medications and polypharmacy in community-dwelling recurrent fallers found a consistent association between the number of medications taken and recurrent falls across the reviewed literature — this is a genuine, additive risk, not simply a marker for being generally unwell.^[8] This is exactly why a structured screen against the AGS Beers Criteria and STOPP/START version 3 (see Assessment & Diagnosis) is worth applying to the whole medication list, not just to the drug the patient suspects.^[6][9]

• Age 65 years or older — dizziness affects over 30% of people in this group.
• Polypharmacy — taking 5 or more regular medications independently and cumulatively raises dizziness and fall risk, even without 1 clearly identifiable culprit drug.
• A new medication or a recent dose change/increase, particularly for an antihypertensive, a diuretic, a sedating drug, or a hypoglycemic agent.
• Renal or hepatic impairment — reduces clearance of many of the relevant drug classes (gabapentin, opioids, benzodiazepine metabolites, aminoglycosides), raising effective exposure without a dose change.
• Frailty, low body weight, or recent acute illness/dehydration — reduces the physiologic reserve to compensate for a medication effect.
• Autonomic neuropathy (longstanding diabetes) or Parkinson disease — both blunt the normal compensatory response to orthostatic stress, compounding a drug's own OH risk.
• A prior fall or near-fall.
• Sensory impairment — vision, hearing, or peripheral proprioception — reduces the redundant sensory input the balance system normally relies on.
• Cognitive impairment — both a risk factor in its own right and a reason symptoms may be under-reported or reported unreliably.
• Living alone or social isolation — delays recognition and correction of an evolving medication problem.
• Alcohol use in combination with any sedating or antihypertensive medication.

The HINTS exam — for continuous vertigo, not for a routine dizziness review

The HINTS exam (Head-Impulse, Nystagmus, Test-of-Skew) is a 3-part bedside oculomotor exam developed to distinguish a peripheral cause (typically vestibular neuritis) from a central cause (typically a cerebellar or brainstem stroke) in a patient with continuous vertigo, nausea, and unsteadiness lasting more than 24 hours. In a trained examiner's hands, a HINTS pattern fully consistent with a peripheral cause is more sensitive for excluding stroke than an early MRI with diffusion-weighted imaging obtained within the first 24-48 hours.^[10] This is a different clinical scenario from the brief, triggered, or medication-related dizziness this chapter otherwise covers — reserve it for genuinely continuous vertigo with a possible central cause, and see the Benign Paroxysmal Positional Vertigo chapter for the full HINTS technique and interpretation table.

History

Ask the patient to describe the sensation in their own words rather than accepting the word "dizzy" at face value — this single step is one of the quality indicators found to be inconsistently documented in routine practice, and is significantly associated with reaching a clinical diagnosis.^[1] Establish timing (episodic vs. continuous), triggers (positional, orthostatic, spontaneous, exertional), and associated symptoms (hearing change, chest pain, headache, weakness) using the TiTrATE framework alongside the 4-category symptom description.^[4] Take a complete medication history including OTC products, herbal/supplement use, and alcohol, and ask specifically and directly: "Did this start, or get worse, after starting a new medication or a dose change?" — correlating the timeline against the pharmacy fill/refill record where available. Ask about falls in the preceding year and about depression/anxiety symptoms, both flagged as under-documented quality indicators in the same Canadian audit.^[1]

Orthostatic vital signs — the technique matters

Orthostatic hypotension is defined by international consensus as a systolic blood pressure drop of at least 20 mmHg, or a diastolic drop of at least 10 mmHg, within 3 minutes of standing.^[5]

1. Have the patient rest supine for at least 5 minutes before the first measurement.
2. Measure blood pressure and heart rate supine.
3. Have the patient stand (or, if standing is not safe, sit upright with legs dependent), and measure blood pressure and heart rate at 1 minute and again at 3 minutes after the position change.^[11]
4. Ask specifically about symptoms (light-headedness, visual dimming, near-faint) at each standing measurement, not only at the end.
5. A measured drop meeting the criteria above, especially if it reproduces the patient's symptom, confirms orthostatic hypotension as a contributor — proceed to Choose Initial Treatment for the medication-adjustment approach.

Structured medication screening tools

Apply the medication list against 2 complementary structured tools rather than relying on memory or a single obvious suspect:

• The 2023 AGS Beers Criteria flags specific drugs and classes as potentially inappropriate in older adults because of CNS effects, anticholinergic burden, or hypoglycemia risk — including benzodiazepines, non-benzodiazepine sedative-hypnotics, first-generation antihistamines, tricyclic antidepressants, and certain sulfonylureas (notably glyburide).^[6]
• STOPP/START version 3 adds explicit criteria for drugs causing orthostatic hypotension and fall risk in older people, alongside START criteria flagging when a needed medication may have been inappropriately withheld — a useful check against over-correcting in the other direction.^[9]

Both tools are decision aids requiring clinical judgment, not automatic stop/start instructions — a flagged drug may still be the right choice for a specific patient once benefits and alternatives are weighed.

Physical examination

Beyond orthostatic vital signs: a basic gait assessment (does the patient rise from a chair and walk safely without assistance?), a cardiac exam (rate, rhythm, murmurs), a screening neurologic exam, and a vision check. Look for medication-specific signs — nystagmus or ataxia suggesting phenytoin toxicity, miosis suggesting opioid effect, or a resting tremor suggesting Parkinsonism contributing to disequilibrium.

Investigations

A point-of-care glucose is quick and directly relevant whenever the pattern is presyncope-like in a patient on insulin or a sulfonylurea. Basic bloodwork (CBC, electrolytes, renal function) helps assess drug clearance and rule out anemia or a metabolic contributor. Obtain an ECG if a cardiac cause is suspected or if a newly started or increased medication affects the QTc. Check a drug level where relevant and available (phenytoin, digoxin, an aminoglycoside) rather than assuming toxicity from the history alone.

Differential diagnosis by category

• Classify the symptom by quality (vertigo/presyncope/disequilibrium/nonspecific) and by timing/triggers to organize the differential efficiently.
• Screen explicitly for red flags before assuming a benign or medication-related cause.
• Identify every medication plausibly contributing, by mechanism, rather than stopping at the first suspect found.
• Correct the reversible medication contribution — through dose reduction, timing change, or substitution — in collaboration with the prescriber, without inappropriately withholding a medication the patient genuinely needs.
• Apply structured screening tools (Beers Criteria, STOPP/START) to the whole medication list, not only to the drug the patient suspects.
• Reduce fall risk through both the medication correction and non-pharmacologic falls-prevention counselling.
• Avoid 2 opposite errors: reflexively adding a vestibular suppressant instead of reviewing medications, and abruptly stopping a needed medication without a taper or follow-up plan.
• Confirm the original indication for any adjusted medication remains adequately treated after the change.

Orthostatic hypotension

Preferred approach dose reduction, a timing change (e.g., moving a diuretic or alpha-blocker dose to bedtime, or dosing an antihypertensive so its peak effect does not coincide with the patient's most active hours), or substitution to a lower-OH-risk agent within the same therapeutic class.^[11] Situational when the drug is genuinely needed for its primary indication (e.g., heart failure, resistant hypertension), accept a monitored, modest symptom with close follow-up rather than under-treating the underlying condition — this is a judgment call made with the prescriber, not a default to stop.

Vestibulotoxicity

Act promptly for a suspected aminoglycoside, vancomycin, or high-dose salicylate contribution — check levels where available, and contact the prescriber urgently, since delay risks permanent injury for the aminoglycoside/vancomycin combination specifically. Reversible salicylate- and quinine-induced vestibulotoxicity typically resolves within days of stopping the drug — this is a genuinely reassuring, actionable teaching point distinct from aminoglycoside risk.

Sedation and CNS depression

Do not stop a benzodiazepine or another chronically used sedative abruptly — withdrawal itself causes rebound anxiety, insomnia, and seizure risk. Preferred approach a structured, gradual taper individualized to the patient, following the Bruyère Research Institute/Deprescribing.org benzodiazepine receptor agonist deprescribing guideline rather than an ad hoc reduction.^[12] For a first-generation antihistamine or anticholinergic used for sleep, allergy, or bladder symptoms, a lower-burden substitute (a second-generation antihistamine, or a non-anticholinergic bladder agent) is often available — discuss with the prescriber rather than simply continuing by default.

Hypoglycemia

Preferred approach adjust insulin or sulfonylurea dosing and timing relative to meals and activity; where glycemic control allows, a lower hypoglycemia-risk regimen (e.g., metformin-based rather than a sulfonylurea, or gliclazide rather than glyburide) is a reasonable substitution to discuss with the prescriber.

Polypharmacy without 1 clear culprit

Preferred approach a full structured deprescribing review against Beers Criteria and STOPP/START, addressing cumulative burden rather than searching indefinitely for a single drug to blame.^[6][9][8]

Falls-prevention counselling

Non-pharmacologic falls-prevention measures apply regardless of the specific medication contribution, and are core, not optional, in every patient with dizziness and any fall risk:

• Home safety review — adequate lighting (including nightlights), removal of loose rugs and clutter from walkways, grab bars in the bathroom, and non-slip mats.^[13]
• Appropriate, well-fitting footwear with good tread; avoid loose slippers and walking in socks alone.
• Vision and hearing checks, since both are redundant inputs the balance system relies on.
• Adequate hydration, and moderation of alcohol intake specifically when combined with a sedating or antihypertensive medication.
• Referral for a structured exercise, balance, or physiotherapy program where fall risk is elevated — this is one of the best-supported non-pharmacologic interventions for reducing falls in older adults.^[13]
• Hip protectors for patients at particularly high fracture risk.

Orthostatic countermeasures

• Rise in stages: sit at the edge of the bed for a moment before standing, rather than going straight from lying to standing.
• Ankle pumps, calf raises, or hand-clenching for 30 seconds before standing to promote venous return.
• Graduated compression stockings for patients with persistent orthostatic hypotension not fully explained or corrected by medication adjustment.
• Adequate salt and fluid intake where not contraindicated by heart failure or significant renal disease — confirm this is appropriate for the individual patient before advising it.

Structured medication review, in practice

• Ask the patient (or a caregiver) to bring every medication and supplement bottle in — including OTC products — for a genuine "brown-bag" review rather than relying on a chart list that may be out of date.
• Build a simple timeline correlating symptom onset against every new drug start and dose change over the preceding weeks to months, rather than assuming the most recently started drug is automatically the cause.
• Screen the full list against the Beers Criteria and STOPP/START, then discuss flagged items with the prescriber as a collaborative recommendation, not a unilateral change.

Patient education

• Explain the specific mechanism identified (orthostatic, sedation, vestibulotoxic, hypoglycemic) in plain language — patients engage better with a change they understand the reason for.
• Never stop a prescribed medication on your own because of a suspicion it is causing dizziness — this is the single most important counselling point, since abrupt discontinuation of some of these drugs (clonidine, benzodiazepines) carries its own genuine, separate risk.
• Rise slowly from lying or sitting, especially first thing in the morning and after meals.
• Keep a simple symptom/timing diary if the cause is not immediately obvious — this becomes genuinely useful data at the next review.
• Know the specific red flags that warrant urgent care rather than waiting for the next scheduled visit (see Red Flags & Refer).
• Bring an updated medication list to every appointment, including any new OTC or supplement purchase.

Older adults and frailty

This is the population this chapter is written for. Physiologic changes with age — reduced baroreceptor sensitivity, reduced renal and hepatic drug clearance, increased body-fat-to-lean-mass ratio prolonging the half-life of lipophilic drugs (many benzodiazepines), and blunted thirst — all raise both the likelihood and the severity of medication-induced dizziness at doses tolerated well in a younger adult. Preferred approach apply the Beers Criteria and STOPP/START to every medication list in this group, not only when dizziness is the presenting complaint, since these are the tools consistently associated in the Canadian literature with a lower rate of recurrent falls when properly applied.^[6][9][8] Avoid benzodiazepines and other sedative-hypnotics as first choice for insomnia, agitation, or delirium in this group — this is a direct Choosing Wisely Canada geriatrics recommendation.^[7]

Diabetes

Autonomic neuropathy blunts the normal compensatory heart-rate and vasoconstrictive response to standing, compounding any antihypertensive's own orthostatic hypotension risk on top of the direct hypoglycemia risk from insulin or a sulfonylurea. Hypoglycemia unawareness — reduced or absent warning symptoms before a low blood glucose — is more common with longstanding diabetes and with recurrent hypoglycemia itself, so dizziness may be a late rather than early sign.

Renal impairment

Reduces clearance of gabapentin, pregabalin, most opioids and their active metabolites, many benzodiazepine metabolites, and the aminoglycosides — raising effective drug exposure without any dose change having been made. Confirm renal dose adjustment specifically for gabapentin and pregabalin, since this is one of the most common and most correctable contributors to excess dizziness in an older adult with reduced kidney function.

Hepatic impairment

Reduces clearance of most benzodiazepines and opioids, prolonging sedative effect; oxazepam and lorazepam are metabolized by glucuronidation rather than hepatic oxidation and are relatively (not absolutely) preferred when a benzodiazepine is genuinely needed in significant hepatic impairment.

Pregnancy

Some degree of orthostatic intolerance is physiologic in pregnancy given normal hemodynamic changes, and is not itself a medication effect in most cases. Avoid unnecessary medication changes for mild, positional, non-red-flag dizziness in pregnancy; confirm any medication adjustment against the drug's own Drug Database entry and the relevant condition-specific chapter for pregnancy-specific guidance.

Parkinson disease

Levodopa-carbidopa and other dopaminergic therapy can itself cause or worsen orthostatic hypotension, on top of the disease's own autonomic involvement — dizziness in this population often needs input from the treating neurologist rather than a simple dose reduction, since under-treating the motor symptoms carries its own real cost.

Reassess within days to a couple of weeks after any medication adjustment made for dizziness — confirm the symptom has genuinely improved, and just as importantly, confirm the original indication for the adjusted drug remains adequately controlled (blood pressure still at goal after a diuretic dose reduction, glycemic control still adequate after a hypoglycemia-risk change, anxiety/insomnia still manageable during a benzodiazepine taper). Repeat orthostatic vital signs at follow-up rather than relying on symptom report alone.

Complications of unaddressed medication-induced dizziness

• Falls and fracture — the most consequential complication, with hip fracture in particular carrying a real risk of lost independence and mortality in older adults; this is the central reason falls-prevention counselling is core to this chapter, not an afterthought.
• Motor vehicle and other accidents — sedating medications specifically raise this risk; counsel accordingly, particularly during any dose titration.
• Medication nonadherence — a patient who attributes dizziness to a needed drug may simply stop taking it without telling anyone, leaving the original condition (hypertension, arrhythmia, diabetes) undertreated; a proactive medication review headed off before this happens is materially better than reacting after the fact.
• A missed serious diagnosis — attributing dizziness to "probably the medication" without adequately screening for red flags risks missing a genuine stroke, cardiac event, or other emergent cause; medication causation and a serious underlying cause are not mutually exclusive possibilities and both need to be actively excluded.
• Loss of confidence and activity avoidance — fear of a further dizzy spell or fall can lead to reduced activity, deconditioning, and social isolation, which in turn worsens both physical fall risk and mood — a cycle worth naming explicitly to the patient.

1. If dizziness persists after a medication adjustment believed to be the cause, first confirm the change was actually made and adhered to, and that enough time has passed for the drug (or its active metabolites) to clear — this varies widely by half-life, from days for a short-acting benzodiazepine to a week or more for a long-acting one or its metabolites.
2. Re-screen the full medication list — a second, less obvious contributor is common in a patient on multiple relevant drugs, and correcting only the first suspect found is a common source of apparent treatment failure.
3. Repeat orthostatic vital signs and re-examine using the TiTrATE framework — a symptom category may become clearer over time or with repeat testing than it was on first presentation.
4. If the pattern now looks specifically like BPPV (brief, positional, triggered vertigo), move to the dedicated BPPV chapter for the Dix-Hallpike-driven work-up rather than continuing a medication-focused review.
5. If a cardiac, neurologic, or vestibular cause not explained by any medication is suspected, refer appropriately (cardiology, neurology, audiology/ENT, or a falls/geriatric medicine clinic for a multifactorial, refractory presentation).
6. Reconsider a psychogenic or anxiety-related contributor specifically when structured medication review and red-flag screening have both been thorough and negative — not as a first assumption.
7. For refractory dizziness in a frail older adult with ongoing polypharmacy, referral to a geriatric medicine or falls-prevention clinic for a comprehensive, multidisciplinary review is a reasonable and often necessary escalation rather than a sign that primary care has failed.

• Reflexively reaching for a vestibular suppressant (an antihistamine or benzodiazepine) instead of reviewing the medication list for a reversible cause.
• Abruptly stopping a medication suspected of causing dizziness without a taper plan — clonidine and chronic benzodiazepine use both carry genuine, separate risks from abrupt discontinuation.
• Measuring "orthostatic vitals" as a single supine-to-standing check without the correct timing (5 minutes supine, then 1 and 3 minutes standing), which can miss a delayed drop.
• Stopping the medication-review process after finding 1 plausible culprit in a patient on multiple relevant drugs, rather than screening the whole list.
• Not asking specifically about OTC products, supplements, and alcohol — patients reliably under-report these unless asked directly.
• Assuming dizziness is medication-related without first screening for red flags — the 2 are not mutually exclusive, and a genuine stroke or cardiac event can coincide with an unrelated medication change.
• Missing hypoglycemia as a cause in a patient on insulin or a sulfonylurea because the presentation looks like ordinary light-headedness rather than a classic hypoglycemic episode.
• Failing to apply a structured screening tool (Beers Criteria, STOPP/START) and relying instead on memory or the most obviously "suspicious-looking" drug.
• Treating polypharmacy-driven cumulative risk as though it must have 1 identifiable culprit drug, rather than addressing the overall burden.
• Not closing the loop with a follow-up visit to confirm both symptom improvement and that the original indication for any adjusted drug remains adequately treated.

How to use this table: this catalogues medications commonly implicated in dizziness, organized by the 4 mechanisms discussed in Recognize the Condition, to support a structured medication review — it is not a treatment menu. Doses shown are typical adult doses only and require patient-specific confirmation, including renal/hepatic adjustment. Select any drug name to open its complete Pharmasist Drug Database page.

Mechanism 1 — Orthostatic Hypotension: Antihypertensives, Diuretics, Alpha-Blockers, TCAs

Confirm with correctly performed orthostatic vital signs (supine 5 minutes, then standing at 1 and 3 minutes) before attributing dizziness to this mechanism.

Mechanism 2 — Vestibulotoxicity: Aminoglycosides, Loop Diuretics, High-Dose Salicylates

Risk rises with cumulative dose, duration beyond about 7-10 days, and renal impairment. Ask specifically about tinnitus and imbalance during any course of these agents.

Mechanism 3 — Sedation and CNS Depression: Benzodiazepines, Opioids, Anticholinergics/Antihistamines, Antiepileptics

Flagged collectively by the AGS Beers Criteria and, for sedative-hypnotics specifically, by Choosing Wisely Canada's geriatrics recommendation. A structured taper, not abrupt discontinuation, applies to chronic benzodiazepine use.

Mechanism 4 — Hypoglycemia: Insulin and Sulfonylureas

Hypoglycemia unawareness is more common in older adults and with autonomic neuropathy, so classic warning symptoms may be blunted.