Grapefruit (Citrus paradisi) is nutritious fruit full of vitamin C, antioxidants, and a tangy-sweet flavor. However, research points to over 85 drug interactions – 43 of which may be serious – with grapefruit. Medications can interact with all forms of grapefruit – the fresh fruit, juice or even the frozen concentrate can result in problems. Interactions may occur with commonly used drugs – such as those that lower cholesterol, treat high blood pressure, or fight cancer.
The dangerous combination of grapefruit and certain medications was discovered about 20 years ago, although many people are still oblivious to this hazardous mix. The effects of mixing them could have potentially serious effects, including sudden death.
This trend of more and more drugs that can produce very serious adverse reactions is worrisome, says Dr. David Bailey, a Canadian clinical pharmacologist.
Taking just one tablet of some medications with a glass of grapefruit juice is like taking 20 tablets with a glass of water, resulting, in other words, with “unintentional overdosing.”
Many of the incompatible drugs are common, such as some cholesterol-lowering statins, antibiotics and calcium channel blockers used to treat high blood pressure.
People older than 45 buy the most grapefruit and take the most prescription drugs, making this group most vulnerable to the dangerous interaction. Also important to note is that all sources of grapefruit, whether the fruit itself or its juice, as well as other fruits from the same family such as Seville oranges (often used in marmalade), limes and pomelos are also not to be mixed with certain medications.
Doctors also warn that the toxic interaction can occur even if someone eats grapefruit or drinks the juice hours before taking the drug, such as drinking the juice at breakfast and taking the medication after dinner.
This page lists medicines with higher risks of serious interactions with grapefruit, but note that the list may not be comprehensive and newer drugs may not be listed. Always consult with your doctor or pharmacist if you have any doubts.