Grapefruit and grapefruit juice have the potential to interact with numerous drugs. While research on drug interactions with grapefruit juice is ongoing, there is a lot of confusing information available on the topic. Scientists and clinical researchers that are experts on the topic agree on the following facts:
• While some prescription medications may interact with grapefruit juice, most do not.
• If you are prescribed a medication that may interact with grapefruit juice and wish to continue consuming this healthy beverage, your physicians often can prescribe non-interacting, alternative medications within the most commonly prescribed drug classes. These medications often can provide the same therapeutic effect with no need to avoid grapefruit juice.
• It is safe to consume grapefruit juice while taking virtually all over-the-counter medications.
• Patients should consult with their pharmacist or doctor if they have any questions about their prescription medication(s).
• Physicians prescribe various drugs for patients in an effort to achieve a desired therapeutic effect, with minimal side effects. Specific cells in our intestines contain enzymes that metabolize (break down) medications, limiting the amount of the drug the body ultimately may absorb. This breakdown or 'clearance' of a drug is generally part of the evaluation of dosage.
Grapefruit juice provides many nutrients, including vitamin C, potassium and lycopene. But chemicals in grapefruit juice and grapefruit pulp interfere with the enzymes that break down (metabolize) various drugs in the digestive system. These include certain calcium channel blockers and cholesterol-lowering drugs. The result can be excessively high levels of these drugs in the blood and an increased risk of potentially serious side effects. Pomelos and Seville oranges (a type of bitter orange often used to make marmalade and compotes) may have a similar effect.
Here's a sampling of drugs known to have potentially serious interactions with grapefruit products:
• Amiodarone (Cordarone). A drug used to treat and prevent abnormal heart rhythms (arrhythmias)