What to consider first in an older adult patient with a history of hypertension, presenting with dizziness, and currently on blood pressure medication, such as lisinopril (angiotensin-converting enzyme inhibitor), metoprolol (beta blocker), or amlodipine (calcium channel blocker)?

Immediate Assessment of Orthostatic Hypotension

The first priority when evaluating dizziness in a patient on blood pressure medication is to measure lying and standing blood pressures to assess for orthostatic hypotension, which is defined as a drop of ≥20 mmHg systolic or ≥10 mmHg diastolic within 3 minutes of standing. 1

Primary Diagnostic Steps

Obtain orthostatic vital signs immediately:

• Measure blood pressure supine after 5 minutes of rest 1
• Repeat measurement within 3 minutes of standing 1, 2
• Document both systolic and diastolic values in each position 1
• Record heart rate changes to assess for autonomic dysfunction 2

This is critical because orthostatic hypotension occurs in approximately 7% of men over 70 years old and carries a 64% increase in age-adjusted mortality, plus increased risk of falls and fractures 1. The condition is particularly common in older adults on antihypertensive medications and can be the direct cause of dizziness symptoms 1.

Medication-Specific Considerations

Review the patient's current antihypertensive regimen for drugs most likely to cause orthostatic hypotension:

• ACE inhibitors (lisinopril): Increase risk of hypotension, dizziness, fatigue, and falls, especially when started at high doses in patients ≥75 years 1
• Beta-blockers (metoprolol): Strong correlation with orthostatic hypotension and baroreflex dysfunction 1
• Calcium channel blockers (amlodipine): Cause dizziness, headache, and edema 1
• Diuretics: May aggravate orthostatic hypotension through volume depletion 1
• Alpha-blockers: Cause postural hypotension and dizziness, especially when combined with diuretics or vasodilators 1

Assessment of Blood Pressure Control

Verify if the patient's blood pressure is being overtreated:

• Check recent blood pressure readings to determine if systolic BP is consistently <140 mmHg 1
• In patients ≥60 years, target systolic BP <150 mmHg is appropriate for most patients to reduce mortality, stroke, and cardiac events 1
• Aggressive BP targets (<140 mmHg) show only small additional benefits with inconsistent results 1
• Consider that older patients may have "brittle hypertension" requiring slow titration 1

Critical Red Flags to Exclude

Assess for symptoms suggesting hypertensive emergency versus medication side effects:

• Postural unsteadiness, visual disturbances, or syncope suggest orthostatic hypotension 1, 2
• New neurological symptoms, chest pain, or severe headache require evaluation for end-organ damage 1
• Cognitive impairment may indicate chronic hypoperfusion from overly aggressive BP control 1

Common Pitfalls

Avoid these diagnostic errors:

• Do not rely solely on seated blood pressure measurements, as this misses orthostatic hypotension 1
• Do not assume dizziness is unrelated to medications without checking orthostatic vitals 1, 2
• Do not continue aggressive BP lowering in elderly patients experiencing dizziness without reassessing targets 1
• Recognize that polypharmacy (particularly in patients ≥75 years) increases risk of potentially inappropriate medications causing adverse drug reactions including falls and dizziness 1

Immediate Management Algorithm

If orthostatic hypotension is confirmed:

1. Review and adjust antihypertensive regimen, particularly beta-blockers, alpha-blockers, and high-dose ACE inhibitors 1
2. Educate patient on non-pharmacological measures: increased water and salt intake, leg crossing, squatting, elastic stockings 2
3. Consider dose reduction or medication discontinuation if BP is below target 1
4. Monitor renal function if adjusting ACE inhibitors or ARBs 1

If orthostatic hypotension is absent:

• Evaluate for other medication side effects (amlodipine-related dizziness occurs independent of orthostasis) 1, 3
• Consider alternative causes of dizziness (vestibular, cardiac arrhythmia, metabolic)
• Reassess appropriateness of current BP targets for the patient's age and comorbidities 1