Grapefruit - Welireg (Belzutifan) Interaction
Herbal: Grapefruit
Also Known As: Citrus paradisi
Drug: Belzutifan
Brand names:
Welireg
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Belzutifan is classified as belonging to the following category: Cytochrome P450 2C19 (Cyp2C19) Substrates
Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP2C19.
In vitro research suggests that grapefruit juice might inhibit CYP2C19 enzymes. Also, a small clinical study shows that taking grapefruit juice with clopidogrel, an antiplatelet prodrug that is metabolized primarily by CYP2C19, decreases plasma levels of the active metabolite and impairs the antiplatelet effect of clopidogrel. This effect is likely due to grapefruit-induced inhibition of CYP2C19.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1
- Holmberg MT, Tornio A, Neuvonen M, Neuvonen PJ, Backman JT, Niemi M. Grapefruit juice inhibits the metabolic activation of clopidogrel. Clin Pharmacol Ther. 2014 Mar;95(3):307-13.
Grapefruit Overview
Grapefruit is a tropical citrus fruit known for its tart and tangy flavor. They are a good source of vitamin C and other nutrients, including vitamin A, potassium, and fiber.
There are several varieties of grapefruits, including white, pink, and red. This color difference is mostly attributed to their respective lycopene content. White grapefruits are the most common and have a slightly bitter taste. Pink and red grapefruits are sweeter and have a more complex flavor.
Grapefruit and grapefruit seed extract is commonly used in dietary supplements for a variety of conditions, such as yeast infections, urinary tract infections, and respiratory infections. It is also sometimes used to treat digestive problems, such as diarrhea and indigestion.
Drug interactions with grapefruit are quite prevalent and if you take prescription medication, you should talk with your doctor or pharmacist first before consuming grapefruit.
Belzutifan Overview
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Belzutifan is used in adults with von Hippel-Lindau disease (VHL; a rare disease that causes tumors and cysts) to treat renal cell carcinoma (RCC; kidney cancer), central nervous system (CNS) hemangioblastomas (tumors in the brain and spinal cord), and a certain type of pancreatic cancer that does not require surgery right away. Belzutifan is in a class of medications called hypoxia-inducible factor inhibitors. It works by blocking the activity of a certain protein in people with VHL.
Grapefruit - More Interactions
Grapefruit interacts with 963 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
© 2021 Therapeutic Research Center, LLC
Drug descriptions are provided by MedlinePlus.
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Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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