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Tuesday 16th July 2019

Warning over mixing grapefruit with pills

27th November 2012

People are generally unaware of the dangers of mixing grapefruit, or grapefruit juice, with certain medications, doctors have warned.


Compounds present in grapefruit can interfere with the breakdown of the medicines in the liver and intestine, leading to potentially dangerous and even fatal overdoses.

Writing in the Canadian Medical Association Journal, a research team at Canada's Lawson Health Research Institute warned the number of drugs known to interact with grapefruit was rising rapidly.

Doctors now know of a total of 43 medications that interact with grapefruit, compared with just 17 in 2008.

Blood pressure and cancer medications, as well as immunosuppressants used to stop the body rejecting a transplanted organ, and statins to lower cholesterol, are among those that react with grapefruit.

According to researcher David Bailey, the effects of grapefruit are so powerful that taking just one tablet with a glass of grapefruit juice can be like taking five or 10 tablets with a glass of water.

The reason behind the effects of grapefruit lies in a group of substances called furanocoumarins, which wipe out one of the body's enzymes that is needed to break the drugs down.

This results in larger amounts of the drug getting into the system than the body can handle, making the difference between therapeutic and toxic levels of the drug, just through drinking grapefruit juice, Bailey said.

For example, patients who took the blood pressure drug felodipine had three times the level of the drug in their bloodstream after they took it with grapefruit juice, compared with taking it with water.

The effects of interactions with grapefruit can vary from stomach bleeding and a changed heartbeat to kidney damage and sudden death.

Bailey's team concluded that the general healthcare community was still largely lacking in knowledge about the dangers of drug interactions with grapefruit.

Professionals faced with a patient in the middle of an adverse event were unlikely to investigate whether or not grapefruit was the cause.

Grapefruit is not the only fruit to interact with drugs: Seville oranges found in marmalade and limes can act in a similar manner.

Experts say that milk can also prevent certain antibiotics from being absorbed if it is taken with the tablets themselves.

They said that pharmacists were generally well-informed about drug interactions, however.

Information about potential interactions was also available in the patient information leaflet included in the packet.


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Wednesday 28th November 2012 @ 1:59

I have never posted before, but this article explains an experience I had recently, after taking two Advils (200mg) with Pink GrapeFruit juice. Within 20 minutes of taking the advils my heart started racing really rapidly. I grew concerned, but by then was seated in the congregation at a funeral. I figured it was a result of just being at the funeral...but I sat there thinking...I did not know the deceased personally, so why should I have such a reaction. It lasted for about 30 minutes. I thought nothing of it after, until now reading this article...I felt the need to share my experience to alert others that even Advil and Grapefruit might be risky.

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