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Difficulty: MediumMedical History Evaluation

A 52-year-old man is evaluated in the outpatient clinic for a 3-week history of generalized muscle weakness, severe leg cramps, and intermittent headaches. He has a past medical history of essential hypertension and gastroesophageal reflux disease. His prescribed medications include amlodipine and famotidine. During the clinical interview, the patient states that he recently discontinued famotidine and began consuming large quantities of a "traditional botanical tea" to naturally manage his frequent heartburn.

Vital signs show a blood pressure of 172/105 mmHg and a pulse of 78/min. Physical examination is unremarkable except for trace bilateral pedal edema.

Laboratory studies reveal:
Serum sodium: 146 mEq/L
Serum potassium: 2.7 mEq/L
Serum chloride: 102 mEq/L
Serum bicarbonate: 32 mEq/L

Which of the following components of the patient's history is the most likely underlying cause of his current clinical and laboratory presentation?

  1. Daily ingestion of a botanical supplement used to treat dyspepsiaAnswer
  2. B
    Unreported frequent use of an over-the-counter proton pump inhibitor
  3. C
    Nonadherence to the prescribed calcium channel blocker therapy
  4. D
    Routine self-medication with nonsteroidal anti-inflammatory drugs
  5. E
    Surreptitious use of a thiazide diuretic to manage pedal edema

Answer

The patient's condition is caused by the daily ingestion of a botanical supplement used to treat dyspepsia, specifically licorice root.
The correct etiology is the daily ingestion of a botanical supplement. The patient presents with severe hypertension, profound hypokalemia, and metabolic alkalosis, a triad strongly indicative of mineralocorticoid excess. His history of consuming a "traditional botanical tea" for heartburn points to licorice root ingestion. Authentic licorice contains glycyrrhizin, which inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 in the renal collecting duct. This enzyme normally converts active cortisol to inactive cortisone. When inhibited, excess cortisol binds to mineralocorticoid receptors, creating a syndrome of apparent mineralocorticoid excess that drives sodium retention, potassium wasting, and hydrogen ion excretion.

Step-by-Step Solution

1
Analyze the patient's vital signs and laboratory results.
The patient exhibits severe hypertension (172/105 mmHg), profound hypokalemia (2.7 mEq/L), and metabolic alkalosis (bicarbonate 32 mEq/L).
Identifying this classic triad is essential to narrow the differential diagnosis to causes of mineralocorticoid excess.
2
Correlate the clinical findings with the patient's medical and social history.
The patient recently started drinking a "traditional botanical tea" in large quantities for heartburn.
Determining the etiology of a new-onset syndrome of apparent mineralocorticoid excess requires eliciting a history of exposures that mimic or artificially increase aldosterone activity.
3
Synthesize the historical exposure with the physiologic mechanism.
The botanical tea likely contains licorice root (glycyrrhizin), which causes the observed clinical picture by inhibiting cortisol metabolism in the kidney.
Licorice root is a common natural remedy for dyspepsia; recognizing its systemic side effects is critical for accurate diagnosis and management.

Key Concept

Identifying over-the-counter and herbal supplements (such as licorice root) in a patient's history is critical when diagnosing the syndrome of apparent mineralocorticoid excess.
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Medical History Evaluation

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