Grapefruit danger up with new drugs
It has been known for a long time that eating grapefruit and taking certain prescription oral medications — including the cholesterol drugs atorvastatin, lovastatin and simvastatin, as well as some cancer and heart drugs — don’t mix.
The team of researchers that discovered the dangerous interactions nearly 20 years ago reported the number of drugs that can cause serious reactions when mixed with grapefruit increased dramatically from 2008-12, from 17 to 43, as new drugs have been introduced.
Writing in a review in the journal CMAJ, the scientists urged physicians who prescribe these medications to learn more about the drugs’ interactions with grapefruit juice.
The culprit ingredients in grapefruit juice, wrote pharmacologist David Bailey of the Lawson Health Research Institute in London, Ontario, and co-authors, are a group of chemicals known as furanocoumarins, which are also found in Seville oranges sometimes used in marmalades, in limes andpomelos.
Furanocoumarins bind to — and thus, inactivate — an enzyme called CYP3A4 that is important for breaking downsome drugs. If the enzyme is inactivated, too much of these medications can remain in a patient’s system for too long, resulting in dangerous side effects including sudden death, kidney failure and gastrointestinal bleeding.