Guanfacine/Grapefruit; Seville Oranges; Star Fruit Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug, changing your diet or commencing any course of treatment.

Medical warning:

Very important. A change in your diet, medicine, or dosage may be necessary. Promptly consult your doctor or pharmacist.

How the interaction occurs:

Guanfacine is processed by enzymes in your intestine. Grapefruit, grapefruit juice, Seville oranges and star fruit contain compounds that slow down this process.

What might happen:

The amount of guanfacine in your blood may increase and cause more side effects than expected.

What you should do about this interaction:

While you are taking this medicine, you should avoid eating grapefruit, grapefruit juice, Seville oranges (e.g. in marmalade), or star fruit. You may choose an alternative citrus beverage (such as orange juice).In the event that you are instructed by a healthcare professional (e.g. doctor, pharmacist, or dietitian) to eat grapefruit, grapefruit juice, Seville oranges or star fruit, before eating them make sure you discuss the effects of these fruits on the blood levels of guanfacine. Your doctor may want to decrease your guanfacine dosage or advise you not to consume grapefruit, grapefruit juice, Seville oranges or star fruit.Your healthcare professionals may be aware of this interaction and may be monitoring you for it. Do not start, stop, or change your medicine or diet before checking with them first.

  • 1.Intuniv (guafacine) US prescribing information. Shire LLC July, 2016. 2.This information is based on or an extract from the UW Metabolism and Transport Drug Interaction Database (DIDB) Platform, Copyright University of Washington 1999-2019...

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.