Taking Drugs with Juice adjusts their effectiveness
Posted Nov 21 2008 4:29pm
Canadian researchers have found that anyone taking medication should beware of drinking fruit juice. Apple, Orange and Grapefruit Juice can all have significant effect of the uptake of drugs, lowering or increasing their effectiveness.
While the influence of grapefruit juice is already well known, and some drug labels caution against drinking it with medicines, this latest research has extended the need for care.
David Bailey, Professor of Physiology, Pharmacology and Medicine at the University of Western Ontario presented the results of his study to the American Chemical Society meeting in Philadelphia yesterday. His study showed that fruit juices can limit the effects of several drugs, including three beta-blockers which are used to treat high-blood pressure, the cancer drug etoposide and some antibiotics.
The study involved healthy volunteers taking fexofenadine, an antihistamine, with either grapefruit juice, water containing naringin – the chemical that causes the fruit’s bitter taste – or plain water. When the medicine was taken with the grapefruit juice, only half of the drug was absorbed into the body, as it was with the water.
Naringin and similar substances in orange and apple juices appeared to bock a “transporter” molecule called OATP1A2 which helps to shuttle drugs from the small intestine to the bloodstream.
Drugs that were boosted in the body by grapefruit juice were affected by a different mechanism that prevented them being broken down.
Professor Bailey originally discovered the drug-boosting effects of grapefruit 20 years ago.
He said: “I’m sure we’ll find more drugs that are affected in this way.” Most medicines should be taken only with water, he said.