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

St. John's Wort is a potent inducer of cytochrome P450 3A4 and P-glycoprotein, causing accelerated metabolism and reduced plasma levels of many 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

Ginger and garlic have antiplatelet properties that can potentiate warfarin's anticoagulant effect, increasing the risk of bleeding.

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

Tyramine-containing herbs and foods can trigger a dangerous hypertensive crisis in patients taking MAOIs because MAOIs prevent tyramine breakdown.

Question 4

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

Accepted Answer

St. John's Wort

Answer

St. John's Wort induces liver enzymes that rapidly metabolize cyclosporine, potentially leading to organ rejection by dropping drug levels too low.

Question 5

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

Accepted Answer

Additive CNS depression and sedation

Answer

Kava's kavalactones exert GABA-A receptor activity, adding to the CNS depressant effects of benzodiazepines and increasing sedation risk.

Herbalism Practice Test

Herbalism Practice Test

Herbalism Herb-Drug Interactions