Thursday, 23 January 2014

BEWARE OF GRAPEFRUIT DRUG INTERACTIONS

Grapefruit and grapefruit juice are good for you -- unless you're on one of an increasingly wide range of medications that interact with them. A report published by CMAJ (Canadian Medical Association Journal) indicates the number of drugs affected by grapefruit juice is on the rise.  More than 85 drugs are now identified as problematic -- and many are commonly used by people over age 45.

The problem centered around compounds in grapefruit called furanocoumarins, which can block an enzyme in the gut that metabolizes certain drugs. This can lead to higher-than-normal levels of certain oral drugs getting into the bloodstream. Less frequently, grapefruit can block drug transporters, leading to an insufficient dose of medication. Just one whole grapefruit or an 8-ounce glass of juice can interact with drugs up to three days after consumption.

Effects vary from person to person. Serious adverse effects can include acute kidney failure, respiratory depression, rhabdomyolysis (muscle breakdown that can lead to kidney damage), gastrointestinal bleeding and torsade de pointes - a potentially fatal increase in heart rhythm.

Current advice from experts is to avoid consuming grapefruit and its juice if you're on a drug that interacts with it. The same recommendation goes for Seville oranges (often used in marmalade), limes, pomelos and tangelos, which have also been found to interfere with drug metabolism. (Sweet oranges, such as navel and Valencia, don't contain furanocoumarins and remain safe to eat.)

In addition, the Food and Drug Administration advises you to:

·     Ask your pharmacist about potential interactions when you fill a prescription.
·    Read the patient information that comes with your prescription and over-the-counter drugs.
·   Check the labels of fruit juices and other drinks to make sure they don't contain grapefruit juice, if you're on one or more drugs that interact.



(Source:  John Hopkins Health Alert, Posted in Healthy Living on 8 January 2014)


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