Two decades ago, Canadian researchers reported an interaction between grapefruit juice and a blood pressure pill called felodipine. Many health professionals are still unaware of the serious nature of this interaction.
The number of drugs known to interact with the furanocoumarins in grapefruit tops 85. More than 40 of these medications have potentially serious interactions with grapefruit as well as pomelos, limes and Seville oranges.
Blood levels of some statin-type cholesterol-lowering drugs triple if grapefruit juice is regularly consumed. In addition to statins, a number of blood pressure pills are affected, as well as the narcotic pain reliever oxycodone. Some medications for treating infections, cancer and cardiovascular disease also interact with grapefruit.
The authors urge healthcare professionals to warn patients about potential interactions. It is not always necessary for people to give up grapefruit, however. Alternate drugs that do not interact might be prescribed, or the physician may be able to prescribe a lower dose of the medication. To avoid serious problems, though, both doctors and patients must be aware of the grapefruit effect and work together to prevent complications.
[Canadian Medical Association Journal, online Nov. 26, 2012]
To learn much more about drugs that interact with grapefruit we suggest you check out our Guide to Grapefruit Interactions. It has a list of medications that can pose problems with grapefruit. You will also read answers to FAQs (frequently asked questions) such as how long the grapefruit effect lingers. For example, is it OK to have half a grapefruit or a glass of grapefruit juice in the morning and take your medication in the evening without experiencing an interaction? Short answer: NO!
