Herbalism Herbal Safety & Contraindications 1 — Questions and Answers
Question 1: Which herb is contraindicated throughout pregnancy due to its potent uterine-stimulating (emmenagogue) properties?
- Lavender
- Pennyroyal (Correct answer)
- Oat straw
- Chamomile
Correct answer: Pennyroyal
Pennyroyal contains pulegone, a hepatotoxic compound that strongly stimulates uterine contractions and has caused miscarriages and maternal deaths.
Question 2: Pyrrolizidine alkaloids (PAs) found in comfrey and coltsfoot raise safety concerns primarily because they are:
- Mild diuretics that strain the kidneys
- Hepatotoxic and potentially carcinogenic with repeated use (Correct answer)
- Strong CNS stimulants
- Known allergens causing respiratory reactions
Correct answer: Hepatotoxic and potentially carcinogenic with repeated use
Pyrrolizidine alkaloids cause veno-occlusive liver disease and are classified as probable human carcinogens; internal use of high-PA herbs is restricted in the US.
Question 3: Ephedra (ma huang) was banned by the FDA in the US as a dietary supplement in 2004 due to serious risks including:
- Severe allergic reactions and anaphylaxis
- Cardiovascular events including heart attack, stroke, and death (Correct answer)
- Liver failure after short-term use
- Acute kidney injury from direct nephrotoxicity
Correct answer: Cardiovascular events including heart attack, stroke, and death
Ephedra's alkaloids (ephedrine, pseudoephedrine) caused numerous cardiovascular events and deaths, leading to an FDA ban on ephedra-containing dietary supplements.
Question 4: Which herb should be used with extreme caution in patients with existing liver disease?
- Peppermint leaf
- Kava kava (Correct answer)
- Nettle leaf
- Calendula
Correct answer: Kava kava
Kava has been associated with rare but serious cases of hepatotoxicity, and patients with liver impairment should avoid it entirely.
Question 5: Aristolochic acid found in Aristolochia species is notorious for causing:
- Thyroid dysfunction
- Aristolochic acid nephropathy and urothelial cancer (Correct answer)
- Severe photosensitivity rash
- Acute pancreatitis
Correct answer: Aristolochic acid nephropathy and urothelial cancer
Aristolochic acid causes permanent kidney damage (aristolochic acid nephropathy) and is strongly associated with urothelial carcinoma.
Question 6: Photosensitizing furanocoumarins are present in which commonly used herbal plant, requiring sun avoidance advice?
- Valerian
- St. John's Wort (Correct answer)
- Ashwagandha
- Milk thistle
Correct answer: St. John's Wort
St. John's Wort contains hypericin, a furanocoumarin that increases skin sensitivity to UV light, potentially causing photosensitivity reactions in fair-skinned individuals.
Herbalism Herbal Safety & Contraindications 1
Which herb is contraindicated throughout pregnancy due to its potent uterine-stimulating (emmenagogue) properties?