Grapefruit Juice Bad Mix With Some Rx Drugs

[lrd]

FYI.

http://www.foxnews.com/story/0,2933,145020,00.html

Grapefruit Juice Bad Mix With Some Rx Drugs
Thursday, January 20, 2005
By Miranda Hitti


Grapefruit juice interacts with many prescription drugs, which can cause potentially serious side effects or make some lifesaving drugs less effective.

This interaction is listed on a medication’s“drug-food interaction” label (search). But many people overlook those labels.

That’s what happened to Lucas King, a 59-year-old retired government auditor. King’s story appeared recently in the American Journal of Nursing. It’s a cautionary tale shared by Amy Karch, MS, RN, an assistant professor of clinical nursing at University of Rochester in New York.


Patient’s Story

At first, King’s health problems had nothing to do with grapefruit juice. Instead, he was facing a high risk of heart disease, like millions of Americans.

King was obese, inactive, and had a family history of heart disease. His LDL “bad” cholesterol level was way too high: 225 mg/dL, even after a month of dieting and exercising.

King’s doctor prescribed Lipitor, along with continued diet and exercise. King obeyed. His Lipitor dose was gradually increased to a high dose of 60 milligrams a day. After four months, he’d brought his LDL cholesterol down to 104. He’d also lost 36 pounds.

Later, King headed to his winter home in Florida. With a grapefruit tree on his patio, he drank two to three daily glasses of fresh grapefruit juice.

But just two months after getting the good news about his cholesterol, King was in a Florida emergency room. His symptoms: muscle pain that had started suddenly, fatigue, and high fever.

King was diagnosed with rhabdomyolysis (search), a severe muscle reaction that can cause death.

Cholesterol-lowering statin drugs (search) such as Lipitor can cause rhabdomyolysis. The possible risk is noted on the drug’s warning labels. In fact, the teaching sheet given to King may have saved his life. The sheet listed signs and symptoms of the condition, advising patients to take them seriously and seek immediate medical attention.

Lipitor was stopped and King was monitored for kidney problems, which rhabdomyolysis can trigger. He said he’d taken the prescribed doses and wasn’t taking any over-the-counter or alternative medicines.

When a nurse asked King if he’d made any changes in diet or exercise, he told her about his grapefruit juice consumption. The nurse looked up Lipitor and found that grapefruit juice slows activity of the liver enzyme that metabolizes Lipitor. This led to high drug levels in King’s body, raising the risk of rhabdomyloysis.


Most Drugs Safe

The Florida Department of Citrus (FDOC) acknowledges that grapefruit juice interacts with some cholesterol-lowering drugs.

The FDOC says grapefruit juice doesn’t interact with most prescription drugs. The FDOC also notes that patients can usually take other drugs in the same drug class that don’t interact with grapefruit juice.

That’s what King did. He was switched to another cholesterol-lowering drug, Pravachol, that doesn’t interact with grapefruit juice.


Drugs That Interact With Grapefruit Juice

Here are some drugs that interact with grapefruit juice. Check with your doctor or pharmacist if you’re concerned about any of your medications:

Xanax, Buspar, Versed, Halcion, Luvox, Zoloft, Allegra, Cordarone, quinidine, Coumadin, Tegretol, Cyclophosphamide, etoposide, ifosfamide, tamoxifen, vinblastine, vincristine, Dextromethorphan (found in many over-the-counter cold medicines), Agenerase, Crixivan, Viracept, Norvir, Fortovase, Proscar, Coreg, Cardizem, Plendil, Cardene, Adalat, Procardia, Nimotop, Sular, Covera, Calan, Verelan, Viagra, Cialis, Theophylline, high cholesterol, Lipitor, Lescol, Mevacor, Zocor, Alfenta, Duragesic, Actiq, Sufenta, Biaxin, Sporanox, erythromycin, troleandomycin.

Patients should check with their doctors about specific interactions between grapefruit juice and medication.


By Miranda Hitti, reviewed by Michael W. Smith, MD

SOURCES: Karch, A. American Journal of Nursing, December 2004. WebMD Medical Reference from Healthwise: “Statins for High Cholesterol.” WebMD Medical Reference from Healthwise: “Selective Serotonin Reuptake Inhibitors.” News release, University of Rochester Medical Center. News release, Florida Department of Citrus.

[Roguish Lawyer]

I take Lipitor. The pharmacist always puts a label on the bottle saying not to drink grapefruit juice with it.

[lrd]

Originally Posted by Roguish Lawyer

I take Lipitor. The pharmacist always puts a label on the bottle saying not to drink grapefruit juice with it.

Reading the fine print is good for your health.

[QRQ 30]

Does that apply to all citrus or just grapefruit? Thai food uses a lot of lemon and lime juice and my wife takes Lipitor and I take SIMVASTATIN for cholesterol. The later is from the VA and may be a generic form of some other name brand.

[Team Sergeant]

Originally Posted by QRQ 30

Does that apply to all citrus or just grapefruit? Thai food uses a lot of lemon and lime juice and my wife takes Lipitor and I take SIMVASTATIN for cholesterol. The later is from the VA and may be a generic form of some other name brand.

After some reading, Doc T said it looks as if it is contained to grapefruit juice. She said it would have stated "citrus" had that been the case.

TS

[Sacamuelas]

I've been offline over the last few days...playing catch-up on the site.

While there are many cases of drug interactions with OTC supplements and everyday food items, this particular interaction being discussed in the article is grapefruit specific. The actual adverse drug effects are caused as a byproduct due to your body’s ineffective ability to break down the drugs when ingested with grapefruit. Grapefruit juice inhibits an important function in your body(an intestinal cytochrome P-450 3A4 system).

The CP-450 system is responsible for the first-pass breakdown (aka metabolism) of numerous medications. This decrease in ability to breakdown certain drugs when ingesting grapefruit can cause an increased bioavailability of the drug and a corresponding increase in serum drug levels. In elderly or compromised patients, this increase may be less tolerated than by others and can be dangerous.

[Razor]

Question for the docs out there. I've seen food interaction instructions for Zocor (Simvastatin) that say to limit grapefruit juice consumption to less than 1qt/day. I infer from this that one doesn't have to completely swear off grapefruit juice, just keep under the suggested level and monitor your body's specific reaction. Is this a reasonable course of action?

[pulque]

I am not familiar with this Journal, but maybe this helps:
Canadian Medical Association Journal

Individuals express CYP3A4 in different proportions, those with the highest intestinal concentration being most susceptible to grapefruit juice–drug interactions. An effect is seen with the whole fruit as well as its juice, so caution should be exercised with both. The precise chemical compound in grapefruit that causes the interaction has not been identified. There is no similar reaction with orange juice, although there is some suspicion that "sour oranges" such as the Seville variety, may have some effect.A recent study, however, that tested the known interference of grapefruit juice with cyclosporine showed no similar effect with Seville oranges.

my bottom line:
-a small amount of grapefruit juice is enough to cause a significant drug interaction with certain drugs
-the effect can last 24 hours after drinking the Grapefruit Juice
-Oranges and other citrus are probably safe
-Someone discovered the Grapefruit/drug effect 16 years ago, yet nobody knows what the precise chemical compound is!!!

[pulque]

Originally Posted by Razor

Question for the docs out there. I've seen food interaction instructions for Zocor (Simvastatin) that say to limit grapefruit juice consumption to less than 1qt/day. I infer from this that one doesn't have to completely swear off grapefruit juice, just keep under the suggested level and monitor your body's specific reaction. Is this a reasonable course of action?

I'm not a doctor, but the article I posted above claims that 250mL of the juice can alter drug metabolism, and also that whole fruit can also have the effect. hope that helps.