Grape - Diovan HCT (Hydrochlorothiazide, Valsartan) Interaction
Herbal: Grape
Also Known As: Vitis vinifera, Activin, Black Grape Raisins, Calzin, Concord Grape, Draksha, Enocianina, European Wine Grape, Extrait de Feuille de Raisin, Extrait de Feuille de Vigne Rouge, Extrait de Peau de Raisin, Extrait de Pepins de Raisin, Feuille de raisin
Drug: Hydrochlorothiazide, Valsartan
Brand names:
Diovan HCT
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Hydrochlorothiazide, Valsartan is classified as belonging to the following category: Cytochrome P450 2C9 (Cyp2C9) Substrates
It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.
In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes. However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism. The effects of continued grape juice consumption are unclear.
Interaction Rating
Likelihood of Occurrence
UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
References
- Greenblatt DJ, von Moltke LL, Perloff ES, et al. Interaction of flurbiprofen with cranberry juice, grape juice, tea, and fluconazole: in vitro and clinical studies. Clin Pharmacol Ther 2006;79:125-33.
- Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extra
- Etheridge, A. S., Black, S. R., Patel, P. R., So, J., and Mathews, J. M. An in vitro evaluation of cytochrome P450 inhibition and P-glycoprotein interaction with goldenseal, Ginkgo biloba, grape seed, milk thistle, and ginseng extracts and their constitu
Grape Overview
Grapes are widely grown and cultivated for a variety of uses such as for food and beverage making (e.g., wine). They also have a long history of use in traditional medicine.
The fruit and skin of grapes contain various compounds that are believed to have health benefits, including antioxidants such as resveratrol and flavonoids. These compounds may help to protect cells from damage and are purported to reduce the risk of certain chronic diseases.
Grapes and grape products may also have anti-inflammatory properties, which may help to reduce inflammation in the body and potentially improve symptoms of certain conditions. Grape seed extracts are also commonly used as a dietary supplement and are often standardized according to the content of polyphenols or proanthocyanidins.
Grape - More Interactions
Grape interacts with 886 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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