Herb Safety & Contraindications Flashcards

Which herbs are most commonly implicated in herb-induced liver injury (HILI) and require monitoring in patients with hepatic disease?

Answer: Kava and comfrey

Kava (Piper methysticum) and comfrey (Symphytum spp.) are among the most well-documented hepatotoxic herbs, and their use is contraindicated in patients with pre-existing liver disease.

Aristolochic acid-containing herbs are contraindicated primarily due to their risk of causing:

Answer: Nephropathy and urothelial carcinoma

Aristolochic acids found in Aristolochia species cause aristolochic acid nephropathy (AAN), progressive renal failure, and significantly increase risk of urothelial cancer.

A patient with gallstones asks about using turmeric in medicinal doses. The key contraindication concern is:

Answer: It may trigger biliary colic by stimulating bile flow

Turmeric and curcumin are cholagogues that stimulate bile flow, which may trigger biliary colic or obstruction in patients with gallstones.

Which herb is contraindicated in patients with kidney disease because it contains oxalates and can exacerbate oxalate kidney stones?

Answer: Wood sorrel / high-oxalate herbs

High-oxalate herbs such as wood sorrel (Oxalis spp.) and large amounts of spinach-family plants can contribute to calcium oxalate kidney stone formation and are avoided in at-risk patients.

Ephedra (Ma Huang) is contraindicated in patients with cardiovascular disease primarily because it:

Answer: Stimulates adrenergic receptors raising heart rate and blood pressure

Ephedrine in Ephedra acts on alpha and beta adrenergic receptors, causing vasoconstriction, tachycardia, and hypertension, which are dangerous in cardiovascular patients.

Which herb is specifically contraindicated in patients with hormone-sensitive cancers (breast, uterine, ovarian) due to phytoestrogenic activity?

Answer: Red clover isoflavones

Red clover (Trifolium pratense) isoflavones (biochanin A, formononetin) have significant estrogenic activity and may promote growth of hormone-sensitive tumors.

Cascara sagrada and senna are contraindicated in patients with intestinal obstruction because they:

Answer: Are stimulant laxatives that increase peristaltic pressure

Anthraquinone laxatives stimulate peristalsis, and in the presence of intestinal obstruction this increased pressure can cause perforation or rupture.