Herbalism Herb-Drug Interactions

Question 1

St. John's Wort is well documented to reduce blood levels of many pharmaceutical drugs primarily because it:

Accepted Answer

Induces CYP3A4 and P-glycoprotein expression

Answer

Inhibits CYP3A4 enzymes

Answer

Blocks drug absorption in the gut

Answer

Increases renal excretion of all drugs

Question 2

Which common herbal anticoagulant interaction poses the greatest risk when combined with warfarin?

Accepted Answer

Ginger and garlic increasing bleeding risk

Answer

Chamomile

Answer

Valerian causing sedation

Answer

Licorice causing fluid retention

Question 3

Patients taking MAO inhibitors (MAOIs) should avoid which herbal supplement due to the risk of hypertensive crisis?

Accepted Answer

Tyramine-rich herbal tonics and fermented preparations

Answer

Lavender

Answer

Ginkgo biloba

Answer

Kava kava

Question 4

Which herb is most likely to interfere with immunosuppressant drugs like cyclosporine following organ transplant?

Accepted Answer

St. John's Wort

Answer

Peppermint

Answer

Slippery elm

Answer

Marshmallow root

Question 5

Kava kava combined with central nervous system depressants such as benzodiazepines may cause:

Accepted Answer

Additive CNS depression and sedation

Answer

Increased drug clearance

Answer

Reduced effectiveness of the benzodiazepine

Answer

Mild stimulatory effects

Question 6

Licorice root (Glycyrrhiza glabra) can potentiate the effects of corticosteroids primarily because glycyrrhizin:

Accepted Answer

Inhibits the enzyme 11β-HSD that breaks down cortisol

Answer

Directly mimics cortisol in the body

Answer

Increases adrenal gland size

Answer

Stimulates the pituitary to release ACTH