grapefruit

Grapefruit is the fruit of a species of citrus tree, Citrus paradisi. Grapefruit, its juice, and other products are consumed widely for their health benefits and medicinal value.

Grapefruit is used medicinally to prevent plaque formation in the arteries (atherosclerosis), to protect against cancer growth, to promote weight loss, and for various other purposes, although, there is little scientific research to back many of its uses.

Grapefruit is a rich source of vitamin C, potassium, pectin, fiber, and other nutrients, and generally makes for a healthy addition to the diet. Studies suggest grapefruit may have antioxidant, antiseptic, digestive, sedative, and antiseptic properties. The fiber content and low calorific value of the fruit may aid weight loss and reduce cholesterol levels. Grapefruit, however, also has certain chemicals that interact with medications, increasing or decreasing their bioavailability and concentration.

Grapefruit contains chemicals known as furanocoumarins that block the action of CYP3A4 enzyme in the intestines, which breaks down many drugs. This allows a higher systemic absorption of these drugs which can result in more side effects and drug toxicity. Cholesterol reducing drugs such as statins, and calcium channel blockers such as felodipine that lower blood pressure is an example of drugs metabolized by CYP3A4.

On the other hand, grapefruit diminishes the bioavailability and effectiveness of certain antihistamine drugs such as fexofenadine, by blocking the activity of proteins known as drug transporters that carry the drug to the cells in the body. While grapefruit, in general, is healthy to consume, individuals taking any regular medications should consult with their healthcare provider before adding it to their diet.

15 grapefruit uses

Suggested uses of grapefruit include the following:

• Atherosclerosis
• Hypercholesterolemia
• Cancer
• Asthma
• Atopic dermatitis
• Psoriasis
• Hematocrit reduction
• Weight loss
• Anorexia
• Infections
• Insomnia
• Prostate enlargement (benign prostate hyperplasia)
• Painful urination (dysuria)
• Diabetes
• Nutritional supplement for vitamin C and potassium

Warnings

• Do not take grapefruit concurrently with drugs metabolized by CYP34A enzyme and drugs that interact with grapefruit.

Common side effects of grapefruit include:

• Reduced red blood cell percentage (hematocrit) in the blood
• Interactions with drugs metabolized by CYP3A4 enzyme

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

No typical dosage

• More than 4 glasses juice/day for pharmacologic effects OR
• 1 to 9 glasses daily, or 240 mL of double-strength juice twice daily

Overdose

• Grapefruit by itself is not toxic, but grapefruit interacts with many common prescription medications. Consumption of grapefruit while taking any of these medications can increase the concentrations of the drug and lead to a drug overdose.
• Some of these drugs can cause serious adverse events including abnormal heart rhythms, muscle damage, kidney damage, respiratory depression and gastrointestinal bleeding. Overdose treatment is supportive and symptomatic, depending on the drug involved.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Severe interactions of grapefruit include:
  • cobimetinib
  • eliglustat
  • fexofenadine
  • finerenone
  • flibanserin
  • isavuconazonium sulfate
  • lomitapide
  • lonafarnib
  • mavacamten
  • naloxegol
  • pacritinib
  • panobinostat
  • regorafenib
  • venetoclax
  • voclosporin
• Grapefruit has serious interactions with at least 89 different drugs.
• Grapefruit has moderate interactions with at least 157 different drugs.
• Grapefruit has mild interactions with at least 55 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

• Normal amounts of grapefruit consumed as part of a healthy diet may be acceptable during pregnancy. Avoid taking excessive amounts of grapefruit if you are pregnant.
• Avoid taking excessive amounts of grapefruit if you are a nursing mother.
• Avoid taking grapefruit without checking with your healthcare provider if you are pregnant or breastfeeding and taking any medications.

• Grapefruit and grapefruit juice normally consumed as part of a healthy diet is likely safe for most people.
• Grapefruit can increase the concentrations, and thereby, the toxicity of many medications. Check with your healthcare provider before adding grapefruit to your diet if you have any health condition and/or you take any regular medication.
• In case you suspect a drug reaction because of consuming grapefruit, contact your physician or Poison Control.