Grapefruit Juice and Medications – Overview
Grapefruit is a citrus fruit known for its tart flavor and health benefits. However, it is believed to interact adversely with some medications.
Is there any truth to that? The answer is yes, and no.
Grapefruit does react with some medications and not with others. That said, more than 85 medications can have a harmful interaction when taken with grapefruit.
The most notable are certain heart disease medications and some pain medications, including opioids.
The problem is caused by a compound called furanocoumarin that is in grapefruit.
Furanocoumarin interferes with an enzyme in the liver that helps break down many prescriptions so that they can be excreted in the urine.
If the enzyme is blocked by grapefruit, the medication stays in the liver longer than it should and could lead to overdose symptoms.
See Also: Grapefruit Diet Plan
Grapefruit Juice Interaction with Different Medications
Just as mentioned above, grapefruit contains a chemical called furanocoumarin, which can block enzymes in your gut and liver.
The said enzymes are responsible for breaking down many drugs before they enter your bloodstream.
If the enzymes can’t break down certain drugs, these medications may build up to harmful levels in your blood.
The interaction between grapefruit and some types of medication results in higher levels of the drug staying in your system for more extended periods than usual.
This can increase the chance of severe side effects, including kidney failure and in the worst-case scenario, sudden death.
Certain medications that shouldn’t be taken with grapefruit include:
Anti-anxiety drugs, including buspirone (BuSpar) and triazolam (Halcion)
Grapefruit juice can cause some prescription drugs, including antidepressants such as sertraline (Zoloft) and fluvoxamine (Luvox).
The Food and Drug Administration (FDA) has warned that grapefruit juice can intensify the effects of some medications.
Grapefruit juice interferes with an enzyme in your small intestine that breaks down many medications.
This means that when you drink grapefruit juice, more of your medication enters your bloodstream than if you didn’t drink it.
So if you drink a lot of grapefruit juice while taking certain antidepressants, there’s a greater chance of side effects or toxicity.
Cholesterol-lowering drugs, including atorvastatin (Lipitor) and lovastatin (Mevacor)
Grapefruit juice contains compounds that prevent the metabolism of certain drugs, resulting in an elevation of levels and toxicity.
Cholesterol-lowering drugs known as statins are a common drug affected by grapefruit juice. Simvastatin (Zocor) is the most potent statin affected by grapefruit juice.
Other statins affected by grapefruit juice include atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol), and Cerivastatin (Baycol).
Grapefruit is a fruit that has been shown to increase the number of certain medications in your blood.
Therefore, if you take medications and drink grapefruit juice, you may be getting “too much medicine” into your body.
Simply put, grapefruit juice can increase the number of many medications in your bloodstream. This can cause more side effects or make the medication less effective.
In some cases, it can even be fatal.
Colchicine used to treat pain from gout or Behcet’s disease
Grapefruit juice can increase the amount of colchicine in the body by decreasing its breakdown. Drinking grapefruit juice while taking colchicine might increase colchicine’s effects and side effects.
Colchicine is a commonly used drug for gout.
A case report described a 71-year-old woman who took 1 mg of colchicine twice daily for gout, together with 200 mL (6 ounces) of grapefruit juice three times daily.
After two weeks, she developed nausea, vomiting, diarrhea, and abdominal pain. Her symptoms started 3 hours after eating grapefruit.
She had to be hospitalized because her symptoms did not respond to treatment.
When her treatment with grapefruit juice and colchicine was discontinued, her symptoms were resolved within two days.
After the incident, she then took the same colchicine dose with orange juice instead of grapefruit juice for six weeks without any adverse events.
That just goes to show that grapefruit juice didn’t react well with the medication.
High Blood Pressure Medication
Grapefruit juice can be a healthy part of a balanced diet, but it can also interact with certain medications in a way that makes them less effective.
The risk is highest with drugs broken down by an enzyme in the small intestine called CYP3A4, which is inhibited by grapefruit and its juice substances.
CYP3A4 metabolizes many drugs, so many different drugs could be affected.
For example, grapefruit juice may make anti-rejection medication for organ transplants less effective at preventing rejection or cause high blood pressure medications not to work and control blood pressure.
One study showed that drinking 200 mL of grapefruit juice three times daily for seven days increased the bioavailability of a drug called tacrolimus, which treats patients who have received organ transplants.
This means that more of the drug could enter the bloodstream and reach its intended target when the patients took their medication with grapefruit juice compared to when they did not drink any grapefruit juice.
Immune system suppressants, such as cyclosporine (Gengraf, Neoral, Sandimmune) and tacrolimus (Prograf)
Grapefruit and grapefruit juice can interact with drugs to alter the effects of some medications.
In the case of tacrolimus, your body may absorb too much of the drug, leading to increased side effects. These may include headache, nausea, diarrhea, vomiting, dizziness, and more.
This is due to a compound in grapefruit called furanocoumarins.
Grapefruits are not the only food to contain this compound — other citrus fruits like pomelos, Seville oranges, and tangelos also contain furanocoumarins.
So it’s essential to be aware of all citrus fruits if you’re taking tacrolimus.
If you take tacrolimus and enjoy eating or drinking grapefruit products, ask your doctor or pharmacist whether this is safe for you.
Grapefruit and grapefruit juice affect many different medications. Therefore, it is essential to check with your healthcare provider before eating this fruit while taking any medication.
Here are some specific examples of how the interaction between grapefruit and medications can occur:
Grapefruit can increase the amount of some medications in your blood, which may cause side effects.
Grapefruit can decrease the number of certain medications in your blood, which may make them less effective.
Grapefruit contains a chemical that your body converts into another chemical that blocks an enzyme that breaks down many drugs in your intestine and liver.
Therefore, fewer drugs are absorbed into your bloodstream.