Grapefruit can cause has adverse effects with newer drugs coming onto the market when they are taken when consuming the juice, according to researchers.
The team of doctors who published their findings in the Nov. 26 edition of the Canadian Medical Association Journal said that many people, including doctors prescribing the meds, were already unaware of the negative effects, including death, with mixing certain older meds with certain foods. But in their study conducted between 2008 and 2012 they find more and more of the new drugs coming into the market are having the same issues.
“Many of the drugs that interact with grapefruit are highly prescribed and are essential for the treatment of important or common medical conditions,” the authors wrote. “Recently, however, a disturbing trend has been seen.”
During the course of the 4-year study, the number of medications with the potential to interact with grapefruit and cause serious problems has increased from 17 to 43 drugs, representing an average increase rate of more than 6 medications per year.
“This increase is a result of the introduction of new chemical entities and formulations,” they wrote. What’s more, there are more than 85 drugs in total that cause some kind of reaction when taken with grapefruit juice, according to the study.
The issue comes when a chemical called furanocoumarins, which is found in some citrus products such as grapefruits, Seville oranges, limes and pomelos, interacts with the medications are absorbed together and metabolized in the gastrointestinal (GI) tract. The chemical causes more of the active medication to enter the bloodstream.
With higher concentrations of certain drugs entering the system it can cause kidney damage, GI tract bleeding, respiratory failure, bone-marrow suppression in people with compromised systems and death.
“Taking one tablet with a glass of grapefruit juice is like taking 20 tablets with a glass of water,” author David Bailey, a clinical pharmacologist at the Lawson Health Research Institute in London, Canada, said to the CBC. “This is unintentional overdosing. So it’s not surprising that these levels go from what we call therapeutic to toxic.”
“Unless health care professionals are aware of the possibility that the adverse event they are seeing might have an origin in the recent addition of grapefruit to the patient’s diet, it is very unlikely that they will investigate it,” the authors wrote. “In addition, the patient may not volunteer this information. Thus, we contend that there remains a lack of knowledge about this interaction in the general healthcare community.”
“Pharmacists are the best port of call for anyone concerned about how their diet may affect their medication,” Neal Patel, from the Head of Corporate Communications Royal Pharmaceutical Society, said to the BBC. “Information about any interactions would always be included in the patient information leaflet that comes with the medicine.”