Eating grapefruit or having a glass of grapefruit juice in the morning can be a healthy way to start your day – the fruit is high in vitamin C and potassium. But the FDA has a video and post on their website reminding consumers that grapefruit can interact with many drugs.10 They explain how grapefruit interacts with these drugs and how they work in the body, especially those taken for high blood pressure or an irregular heartbeat. Grapefruit juice can increase or decrease the amount of certain drugs that enter our blood stream. When it raises the level of a drug in our system, it can cause more side effects. For example, “with certain statins that lower cholesterol levels, such as Zocor [simvastatin] and Lipitor [atorvastatin], it’s important to avoid grapefruit and grapefruit juice consumption because it can raise statin levels in the blood and increase the risk for serious side effects,” according to Stacy Kennedy, MPH, RD, a senior clinical nutritionist at the Dana-Farber/Brigham and Women’s Cancer Center in Boston and co-founder of Wellness Guides, a health and wellness practice in Wellesley, Massachusetts.  Grapefruit can increase the absorption of statins and lead to symptoms like dizziness, muscle pain, liver damage and kidney failure, adds Chan.  Here are some types of drugs that may interact with grapefruit and grapefruit juice:
Some drugs that treat high blood pressure, such as Procardia XL (nifedipine)
Some organ-transplant rejection drugs, such as Sandimmune and Neoral (both cyclosporine)
Some anti-anxiety drugs, such as buspirone
Some corticosteroids that treat Crohn’s disease and ulcerative colitis, such as Uceris (budesonide)
Some drugs that treat abnormal heart rhythms, such as Pacerone and Nexterone (both amiodarone)
Some antihistamines, such as Allegra (fexofenadine)
For a further list of drugs that interact with grapefruit, check out the appendix of this review on grapefruit’s interactions with medications.11 If you eat grapefruit or drink grapefruit juice and are taking any of these medications, talk it over with your doctor. You can also read the medication guide or patient information sheet that comes with your prescription drugs to see if there is a grapefruit juice warning. For OTC (over-the-counter) drugs, check out the Drug Facts label on the bottle. If you have to avoid grapefruit and grapefruit juice, pay attention to the labels of other fruit juices as they may contain grapefruit juice. Seville oranges, pomelos and tangelos can have the same effect on drugs as grapefruit, so it’s best to avoid those fruits as well if you know your drug can interact with grapefruit. Opt for other fruits like kiwi, blood oranges and other fresh produce instead, Kennedy suggests.