Definition of Drug - Herb Interaction

Pharmaceutical drugs, including over-the-counter medications, can interact with compounds found in medicinally active herbs. These drug-herb interactions are relatively common and can be beneficial or dangerous.

Synergistic Effects

• Many herbs potentiate the effects of synthetic drugs. For example, the pineapple-sourced enzyme bromelain can enhance the effectiveness of non-steroidal anti-inflammatories (NSAIDs).

Decreased Effects

• Certain herbs may inhibit the effectiveness of prescription drugs. The popular immunostimulant goldenseal can increase platelet activity, thereby diminishing the effects of anticoagulants like warfarin.

Overdose-Like Symptoms

• Herbs and drugs that contain similar compounds can cause overdose-like symptoms. Saint John's Wort, which may act as a serotonin-selective reuptake inhibitor (SSRI) can cause serotonin syndrome---life-threatening condition---in patients taking other SSRIs like Paxil.

Considerations

• Anyone taking prescription or over-the-counter drugs on a regular basis should consult a qualified expert before taking any herbal supplement. Simple precautions can prevent life-threatening drug-herb interactions.

Misconceptions

• Unless a physician has directed otherwise, patients taking pharmaceutical drugs do not need to avoid the culinary use of common herbs and spices. High-dose extracts---not seasonings---are responsible for almost all drug-herb interactions.