An adult hypertensive patient on spironolactone, furosemide, amlodipine and clopidogrel presents with unsteady gait, impaired renal function (elevated BUN and creatinine) and mild hyponatremia; what are the likely causes of the gait disturbance and what immediate management should be undertaken?

Immediate Management of Unsteady Gait in a Hypertensive Patient on Multiple Diuretics with Hyponatremia and Renal Impairment

Most Likely Cause and Immediate Action

The unsteady gait is most likely caused by hyponatremia (sodium 130 mEq/L) from excessive diuretic therapy, compounded by volume depletion and possible medication toxicity; you must immediately hold both furosemide and spironolactone until sodium normalizes above 135 mEq/L. 1

The combination of spironolactone and furosemide with elevated creatinine (1.8 mg/dL) and BUN (73 mg/dL) indicates volume depletion and worsening renal function from over-diuresis. 2, 3

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Immediate Diagnostic and Management Steps

Hold Diuretics Immediately

• Stop both furosemide and spironolactone immediately when sodium is 130 mEq/L, as the American College of Cardiology mandates holding all diuretics when sodium falls below 135 mEq/L. 1
• Do not restart diuretics until sodium normalizes above 135 mEq/L. 1
• The creatinine of 1.8 mg/dL exceeds the safety threshold for spironolactone (should be <2.0-2.5 mg/dL), making continuation dangerous. 1

Assess Volume Status Clinically

• Examine for signs of volume depletion: orthostatic hypotension, dry mucous membranes, decreased skin turgor, flat neck veins. 2
• Check for neurological symptoms of hyponatremia: confusion, lethargy, headache, nausea, seizures (in severe cases). 1
• The unsteady gait may represent early neurotoxicity from hyponatremia, which can progress to more serious complications if not corrected. 1

Laboratory Monitoring

• Recheck electrolytes (sodium, potassium, magnesium), BUN, and creatinine within 24-48 hours after holding diuretics. 1, 4
• Monitor daily until sodium exceeds 135 mEq/L. 1
• Check serum osmolality and urine sodium/osmolality to confirm hypovolemic hyponatremia versus SIADH (though volume depletion is most likely given the clinical picture). 1

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Addressing the Renal Impairment

Distinguish Volume Depletion from Worsening Heart Failure

• If there are NO signs of fluid retention (no edema, no jugular venous distension, no dyspnea), the elevated BUN/creatinine ratio (>20:1) strongly suggests prerenal azotemia from volume depletion. 2

• In this scenario, hypotension and azotemia will likely resolve after reducing or holding diuretics. 2

• If signs of fluid retention persist despite elevated creatinine, this represents worsening heart failure with declining renal perfusion—an ominous scenario requiring careful reassessment of the entire regimen. 2

Common Pitfall to Avoid

• Excessive concern about mild azotemia can lead to under-diuresis and refractory edema, but in this case the sodium of 130 mEq/L and elevated BUN/creatinine ratio clearly indicate over-diuresis, not under-diuresis. 2
• Small increases in creatinine are acceptable during active diuresis only if the patient remains asymptomatic and congestion improves—but unsteady gait is a symptom requiring immediate action. 2, 5

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Medication Review and Adjustments

Spironolactone Safety Concerns

• Spironolactone should only be used when creatinine is <2.0-2.5 mg/dL per ACC/AHA guidelines; at 1.8 mg/dL, the patient is approaching the upper safety limit. 1
• Spironolactone requires potassium <5.0 mEq/L before initiation, and although potassium is currently 4.2 mEq/L, the combination with impaired renal function increases hyperkalemia risk. 1, 3
• Spironolactone can cause hyponatremia, especially early in treatment, and ongoing use is associated with hyponatremia (adjusted OR 1.75). 2, 6

Furosemide and Hyponatremia

• Newly initiated furosemide is associated with hyponatremia (adjusted OR 1.23), but ongoing use is actually protective (adjusted OR 0.52), suggesting that if furosemide has been used long-term, other causes of hyponatremia should be sought. 6
• However, the combination of furosemide with spironolactone increases electrolyte depletion risk markedly. 2

Drug Interactions Contributing to Renal Dysfunction

• The combination of furosemide with ACE inhibitors or ARBs (if the patient is on one) can lead to severe hypotension and deterioration in renal function, including renal failure. 4

• Although the patient is not listed as taking an ACE inhibitor or ARB, if one is part of the regimen, dose reduction or temporary interruption may be necessary. 4

• NSAIDs should be avoided, as they block diuretic effects and increase the risk of renal dysfunction. 1, 4

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Blood Pressure Management During Diuretic Hold

Continue Amlodipine

• Amlodipine should be continued as it does not cause electrolyte disturbances and will help maintain blood pressure control while diuretics are held. 2, 7
• Calcium channel blockers like amlodipine are first-line therapy for hypertension and do not worsen renal function or electrolyte balance. 2, 7

Monitor Blood Pressure Closely

• Check blood pressure daily while diuretics are held to ensure hypertension does not worsen. 1
• If blood pressure rises significantly (>160/100 mmHg), consider adding or increasing a non-diuretic antihypertensive agent rather than restarting diuretics prematurely. 2

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Restarting Diuretics After Sodium Normalizes

When to Restart

• Do not restart diuretics until sodium is >135 mEq/L and the patient is clinically stable. 1
• Reassess volume status: if the patient has no signs of fluid overload (no edema, no dyspnea, no elevated JVP), diuretics may not be needed at all. 2

How to Restart

• If diuretics are needed, restart furosemide alone at a lower dose (e.g., 20 mg daily) and monitor electrolytes every 2-3 days. 2, 1, 5
• Do not restart spironolactone until renal function improves (creatinine <1.5 mg/dL ideally) and sodium remains stable >135 mEq/L for at least 1 week. 1
• If spironolactone is restarted, use the lowest dose (12.5-25 mg daily) and monitor potassium and creatinine within 1 week, then at 1 month, 3 months, and 6 months. 2, 1

Avoid Combination Therapy Initially

• Spironolactone should never be used as monotherapy and requires concomitant loop diuretic, but the combination increases electrolyte disturbance risk. 1
• The combination of spironolactone with ACE inhibitors and ARBs has not been adequately studied for safety, so if the patient is on an ACE inhibitor or ARB, consider switching to amlodipine-based therapy instead. 1

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Addressing the Unsteady Gait Specifically

Neurological Evaluation

• Perform a focused neurological examination to assess for cerebellar signs, peripheral neuropathy, or vestibular dysfunction. 1
• Check for orthostatic hypotension (blood pressure drop >20 mmHg systolic or >10 mmHg diastolic upon standing), which can cause unsteady gait and is common with volume depletion. 4

Medication-Related Causes

• Amlodipine can cause peripheral edema and dizziness, which may contribute to unsteady gait, but is less likely to be the primary cause given the hyponatremia. 2
• Clopidogrel does not typically cause gait disturbance, but ensure the patient is not experiencing bleeding complications (e.g., subdural hematoma) if there is a history of falls or trauma. 2

Hyponatremia as the Primary Culprit

• Hyponatremia at 130 mEq/L can cause gait instability, confusion, and falls, especially in elderly patients. 1
• Correcting sodium to >135 mEq/L should resolve the gait disturbance if hyponatremia is the cause. 1

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Long-Term Management Strategy

Optimize Blood Pressure Control Without Excessive Diuresis

• Target blood pressure <130/80 mmHg using amlodipine as the cornerstone, adding a thiazide diuretic (hydrochlorothiazide or chlorthalidone) only if needed once renal function stabilizes. 2, 7
• Thiazides lose effectiveness at creatinine clearance <40 mL/min (estimated GFR ~40 mL/min with creatinine 1.8 mg/dL), so loop diuretics are preferred if diuresis is required. 1, 8

Avoid Polypharmacy Pitfalls

• The patient is on four medications (spironolactone, furosemide, amlodipine, clopidogrel), which increases the risk of drug interactions and adverse effects. 4
• Simplify the regimen by eliminating spironolactone if possible and using furosemide only when clinically indicated for fluid overload. 1

Monitor Electrolytes and Renal Function Regularly

• Check electrolytes and renal function every 3-6 months once stable, and more frequently (every 1-2 weeks) during any medication adjustments. 1, 5
• Watch for signs of volume depletion (hypotension, worsening azotemia, decreased exercise tolerance) and adjust diuretics accordingly. 2, 5

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Summary of Immediate Actions

1. Hold furosemide and spironolactone immediately. 1
2. Recheck electrolytes (sodium, potassium, magnesium), BUN, and creatinine within 24-48 hours. 1, 4
3. Assess volume status clinically (orthostatic vitals, jugular venous pressure, edema). 2
4. Continue amlodipine for blood pressure control. 2, 7
5. Monitor blood pressure daily while diuretics are held. 1
6. Do not restart diuretics until sodium >135 mEq/L. 1
7. Perform neurological examination to assess gait disturbance and rule out other causes. 1
8. Avoid NSAIDs and review all medications for potential interactions. 1, 4