Grapefruit juice and the actual grapefruit can be part of a healthy diet. It has Vitamin C and potassium, nutrients that your body needs. But it isn’t good for you when it affects the way your medicines work, especially if you have high blood pressure or arrhythmia (irregular or abnormal heart beat), says the United States Food and Drug Administration (USFDA).

This food and drug interaction can be a concern, says USFDA’s Shiew Mei Huang. In fact, the FDA requires some prescription and over-the-counter drugs that are taken orally to include warnings against drinking grapefruit juice or eating grapefruit while taking the drug, Huang says.

Here are some types of drugs that grapefruit juice can cause problems with on interaction: Some statin drugs to lower cholesterol, such as Zocor (simvastatin) and Lipitor (atorvastatin); some drugs that treat high blood pressure, such as Procardia and Adalat CC (both 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 or ulcerative colitis, such as Entocort EC and Uceris (both budesonide); some drugs that treat abnormal heart rhythms, such as Pacerone and Nexterone (both amiodarone) and some antihistamines, such as Allegra (fexofenadine).

Grapefruit juice does not affect all the drugs in the categories above. The severity of the interaction can vary, the agency says.

Source: USFDA