Grapefruit juice and statins

Many a times a bottle of prescription drugs state"do not eat grapefruit or drink juice when taking this medicine".

The enzyme important in breakdown of a chemical in grapefruit juice is also involved in breakdown of certain drugs.

The molecule called cyP3A4 resides in liver,colon,small intestine.

Thus if cyP3A4 enzymes are preoccupied in breakdown of grapefruit juice you just drank,there will not be enzymes available to breakdown medications.

In 1989,a group of Canadian scientists were studying interactions of ethanol on felodipine taken for high bp.The scientists used grapefruit juice to disguise taste of ethanol and observed differences 

regarding amount of drug in blood stream.It was five times mor in blood stream of people who drank medicine with grapefruit juice compared to when it was taken with water.