Grapefruit - Niaspan (Niacin (prescription drug)) Interaction
Herbal: Grapefruit
Also Known As: Citrus paradisi
Drug: Niacin (prescription drug)
Brand names:
Niaspan, Niacor
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
There were no interactions found between Niacin (prescription drug) and Grapefruit. This does not mean the potential for an interaction does not exist, however. There is often a lack of studies and data surrounding traditional medicine, especially concerning drug interactions, so it is important to always consult your provider before making any changes to your medication regimen.
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.
Niacin (prescription drug) Overview
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Niacin is used with diet changes (restriction of cholesterol and fat intake) to reduce the amount of cholesterol (a fat-like substance) and other fatty substances in your blood and to increase the amount of high density lipoprotein (HDL; ''good cholesterol''). Niacin can be used in a number of situations including the following:
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alone or in combination with other medications, such as HMG-CoA inhibitors (statins) or bile acid-binding resins;
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to decrease the risk of another heart attack in patients with high cholesterol who have had a heart attack;
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to prevent worsening of atherosclerosis (buildup of cholesterol and fats along the walls of the blood vessels) in patients with high cholesterol and coronary artery disease;
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to reduce the amount of triglycerides (other fatty substances) in the blood in patients with very high triglycerides who are at risk of pancreatic disease (conditions affecting the pancreas, a gland that produces fluid to break down food and hormones to control blood sugar).
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Niacin is also used to prevent and treat pellagra (niacin deficiency), a disease caused by inadequate diet and other medical problems. Niacin is a B-complex vitamin. At therapeutic doses, niacin is a cholesterol-lowering medication.
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Results of a clinical study in people with heart disease and well-controlled cholesterol levels that compared people who took niacin and simvastatin with people who took simvastatin alone and found similar results for the two groups in the rate of heart attacks or strokes. Taking niacin along with simvastatin or lovastatin also has not been shown to reduce the risk of heart disease or death compared with the use of niacin, simvastatin, or lovastatin alone. Talk to your doctor if you have questions about the risks and benefits of treating increased amounts of cholesterol in your blood with niacin and other medications.
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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