Kava kava interacts with levodopa by which mechanism?

Kava kava interacts with levodopa by which mechanism?

• A. Decreased absorption of levodopa
• B. Increased absorption of levodopa
• C. No interaction
• D. Increased levodopa metabolism

Answer: (A)

This item tests how an herb can alter the gut absorption of a medication. Levodopa’s effectiveness relies on its absorption in the small intestine, which is sensitive to anything that slows gastric emptying or changes the gut environment. Kava kava contains compounds that can affect gastrointestinal motility and the intestinal milieu, leading to less levodopa being absorbed into the bloodstream. That’s why the mechanism is decreased absorption of levodopa. It’s unlikely that kava kava would increase absorption, and there is a real interaction rather than none at all. Increased metabolism would imply oxidation or breakdown of levodopa by enzymes more active because of the herb, but levodopa is primarily decarboxylated peripherally, and kava’s effects don’t provide a clear mechanism for speeding that process in a way that would raise clearance of levodopa. In practice, expect potential reduction in levodopa bioavailability when combined with kava kava, which can lessen therapeutic benefit.

This item tests how an herb can alter the gut absorption of a medication. Levodopa’s effectiveness relies on its absorption in the small intestine, which is sensitive to anything that slows gastric emptying or changes the gut environment. Kava kava contains compounds that can affect gastrointestinal motility and the intestinal milieu, leading to less levodopa being absorbed into the bloodstream. That’s why the mechanism is decreased absorption of levodopa.

It’s unlikely that kava kava would increase absorption, and there is a real interaction rather than none at all. Increased metabolism would imply oxidation or breakdown of levodopa by enzymes more active because of the herb, but levodopa is primarily decarboxylated peripherally, and kava’s effects don’t provide a clear mechanism for speeding that process in a way that would raise clearance of levodopa. In practice, expect potential reduction in levodopa bioavailability when combined with kava kava, which can lessen therapeutic benefit.