"grapefruit juice" news and stories

In 1989, a group of Canadian researchers discovered that grapefruit juice increased the potency of a blood pressure drug they were testing. The pairing came about after they tried to use the juice to mask the taste of the alcohol; the trial was held to uncover potential side effects when the alcohol was combined with the drug. The scientists were startled, but had difficulty proving why the grapefruit juice had such an effect. According to the New York Times, studies done on grapefruit juice have concluded that it sometimes interferes with an enzyme, CYP 3A4, which can reduce the potency of many drugs or help them pass out of the body faster. This means that the body might receive more of an impact from a given drug if it is taken with grapefruit juice.

Grapefruit juice does not always produce this effect, however. It interacts with CYP 3A4 in the intestines, so it does not effect injected drugs, only those taken orally. It also is very unpredictable. Different people have different amounts of CYP 3A4 in their intestines and different glasses of grapefruit juice will react differently. It is most likely to produce potentially harmful effects with cholesterol-lowering drugs and SSRIs, like Prozac, which is used to treat depression. The best thing to do is to avoid grapefruit juice if your doctor recommends it.

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