grapefruit CAN counteract with certain meds

Grapefruit juice contains chemicals that can cause problems with enzymes that break down certain types of medicines in your intestines. When a medicine does not get broken down properly in the intestines, you can have too much medicine in your blood. The chemicals in grapefruit juice can also cause you to have not enough medicine in your blood. Having too much medicine in your blood increases your chances of having side effects