Study finds danger in mixing drugs and grapefruit juice

WASHINGTON - Drinking grapefruit juice to wash down some prescription medicines may be dangerous.

The juice can raise blood concentrations of the drug above what the dosage calls for, say researchers.

Unlike other citrus juices, grapefruit juice inhibits one of the body's intestinal enzyme systems and can result in marked increases in serum levels of some prescription drugs, such as those to treat heart disease and control blood pressure.

Interactions between grapefruit juice and certain drugs - which has been known but not extensively studied - are particularly worrisome for the elderly, who are more likely to take medications and may be inclined to drink calcium-fortified grapefruit juice, Mayo Clinic researchers Garvan Kane and James Lipsky say in the Mayo Clinic Proceedings.

Although some drugs are given with others to enhance their effects, grapefruit juice should not be used for this purpose because its impact can be potentially dangerous, they say.

However, grapefruit juice is not a problem for those receiving medication intravenously, the report says.

- REUTERS