Q. Ive heard about possibly dangerous interactions between grapefruit juice and certain medications. Could you print a list of these?
A. The grapefruit juice interaction first came to light with the calcium blockers felodipine and nifedipine. People who washed down these drugs with grapefruit juice were unaware the juice caused an overdose.
Enzymes in the intestines and liver break down drugs so the body can eliminate them. Grapefruit juice contains natural substances that block the action of some of these enzymes, primarily in the intestines.
The result is that certain orally taken drugs can build up to excessive levels in the blood.
This effect, to some extent, can last for three days or so following the last glass of juice.
In addition to grapefruit juice, some studies suggest the fruit also interacts.
Here is a list of medications known to show an increased drug effect when taken with grapefruit.