Licorice (Glycyrrhiza glabra)

One of the top 10 herbal medications utilized in USA.

Historically used to improve immune function and treat a variety of conditions including PUD, duodenal ulcers, cough and/or bronchitis, atherosclerosis, chronic fatigue syndrome, various cancers, AIDS, and Addison disease. Most recently a study has demonstrated its effectiveness in relieving postop sore throat.

Unknown. Theoretical problems in pts with impaired renal function, Htn, chronic liver disease, cardiac arrhythmias, and hypertonia.

Potential for drug interactions. Pseudohyperaldosteronism has been produced experimentally in healthy subjects taking >100 g/wk.

Pseudohyperaldosteronism: Documented mineralocorticoid effects that result in fluid retention, hypernatremia, hypokalemia, and edema.

Hypertension: Direct effects on vascular smooth muscle tone independent of mineralocorticoid properties.

Vasospasm and/or headache: Recent case reports of cerebral artery spasm causing severe headache, visual disturbances, and potential ischemia.

Hypokalemia and/or muscle weakness: Chronic usage related to hypokalemic myopathies, muscle cramps, and skeletal muscle spasms.

Arrhythmias: Rare side effect but more worrisome in pts with Hx of arrhythmias requiring medication (e.g., digoxin).

Paresthesias: Numbness in extremities may be a sign of licorice toxicity.