What is a medicine interaction?

A medicine interaction is when a medicine or food changes how another medicine works.

How does grapefruit interact with medicines?

Eating grapefruit or drinking grapefruit juice can cause some medicines to enter your body faster. This makes it more likely that you will have side effects from the medicine.

Interactions can happen up to three days after eating or drinking grapefruit. This means you cannot drink grapefruit juice in the morning and take your medications later in the day to stop possible medicine interactions.

Do all medicines interact with grapefruit?

Only some medicines interact with grapefruit. Examples include medicines for:

• High cholesterol: atorvastatin (one brand: Lipitor) and simvastatin (one brand: Zocor)

• High blood pressure: felodipine (one brand: Plendil), nifedipine (one brand: Procardia), and nisoldipine (one brand: Sular)

• Heart arrhythmia (when your heartbeat isn’t normal): amiodarone (one brand: Cordarone) and disopyramide (one brand: Norpace)

If you don’t know if the medicine you are taking interacts with grapefruit, ask your doctor or pharmacist. Your doctor usually can prescribe another medicine that doesn’t interact with grapefruit.

Do all fruit juices interact with medicines?

All other fruit juices, even other citrus juices, are safe to drink when taking medicine. There is no proof that these other juices interact with medicines.

What if I take a medicine that interacts with grapefruit?

An interaction can occur even if you eat or drink a small amount of grapefruit. However, if you like grapefruit and want to continue to enjoy it, ask your doctor if there is a different medicine for you that doesn’t interact with grapefruit.