Navigation Links
More New Drugs a Bad Fit With Grapefruit, Study Finds
Date:11/26/2012

By Steven Reinberg
HealthDay Reporter

MONDAY, Nov. 26 (HealthDay News) -- Because of new chemical formulations, prescription drugs that interact badly with grapefruit have more than doubled in number since 2008, yet many doctors seem unaware of this, Canadian researchers report.

"The number of drugs on the market with the potential to produce serious adverse and in many cases life-threatening effects when combined with grapefruit has markedly increased over the past few years from 17 to 43 in four years," said lead researcher David Bailey, from the Lawson Health Research Institute in London, Ontario.

"There is much greater need for health care professionals to understand grapefruit/drug interactions and to apply this information to the safer use of these drugs in their clinical practice," Bailey said.

Even small amounts of grapefruit or grapefruit juice have the potential to cause sudden death, acute kidney failure, respiratory failure, gastrointestinal bleeding and other serious side effects when paired with these medications. Included are certain cholesterol-lowering medications, blood pressure drugs, cancer treatments and antibiotics such as erythromycin, the researchers said.

According to their review article, published Nov. 26 in the Canadian Medical Association Journal, more than 85 drugs may interact with grapefruit. Forty-three of these can have serious side effects, the researchers said.

Citrus fruits such as limes and Seville oranges, often used in marmalade, also contain the active ingredients -- called furanocoumarins -- that cause the dangerous interactions, the researchers said. The chemicals apparently inhibit an enzyme that normally deactivates about half the effects of medication.

All the drugs that interact with these chemicals are taken orally and don't metabolize well, meaning much of the drug passes through the body without entering the bloodstream. All are metabolized in the stomach in the same way, the researchers said.

A small amount of grapefruit, even ingested hours before taking the medications, can increase the amount of the drug metabolized, which is like taking many doses at once, the researchers said.

The toxic effect can build when the drug is taken repeatedly. For example, if the cholesterol-lowering drug Zocor is combined with a 7-ounce glass of grapefruit juice once a day for three days, the drug in the bloodstream will increase 330 percent, Bailey said.

According to the report, drugs that can interact with grapefruit include:

  • Certain cholesterol-lowering statin drugs, such as Zocor (simvastatin), Lipitor (atorvastatin) and Pravachol (pravastatin),
  • Some blood pressure-lowering drugs, such as nifedipine (Nifediac and Afeditab),
  • Organ transplant rejection drugs, such as cyclosporine (Sandimmune and Neoral),
  • Certain cardiovascular drugs, such as amiodarone (Cordarone and Nexterone), clopidogrel and apixaban.

Because people older than 45 are the major buyers of grapefruit and are more likely than younger individuals to take a variety of medications, they are most at risk. Also, because of their advanced age, they are most vulnerable to the harmful reactions of grapefruit-drug combinations, the researchers said.

Dr. Gregg Fonarow, a spokesman for the American Heart Association and a professor of cardiology at the University of California, Los Angeles, said little is known about how often these adverse effects occur in real world practice. Further studies are necessary, he added.

"Patients taking medications where there are potentially serious adverse interactions should, in general, be advised to avoid consumption of moderate or large quantities of grapefruit, or together with their physician consider potential alternative medications that are not metabolized by the liver enzyme inhibited by grapefruit," Fonarow said.

More information

For more information on drug interactions, visit the U.S. National Library of Medicine.

SOURCES: David Bailey, Ph.D., Lawson Health Research Institute, London, Ontario, Canada; Gregg Fonarow, M.D., spokesman, American Heart Association, professor of cardiology, University of California, Los Angeles; Nov. 26, 2012, Canadian Medical Association Journal


'/>"/>
Copyright©2012 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Continued Use of ADHD Drugs May Reduce Criminal Behavior, Study Says
2. UAlberta prostate cancer researcher and team developing homing beacon drugs to target cancer cells
3. Can breast cancer cells reaction to cancer drugs be predicted?
4. Quick, high-volume test offers fast track in search for Alzheimers drugs
5. Structure of enzyme unravelled providing basis for more accurate design of chemotherapeutic drugs
6. Injectable sponge delivers drugs, cells, and structure
7. Game changer for arthritis and anti-fibrosis drugs
8. First trial in humans of minicells: A completely new way of delivering anti-cancer drugs
9. Testing pain killers on humans could save money and speed the arrival of new drugs
10. Patients with aberrations in two genes respond better to drugs blocking a well-known cancer pathway
11. New Diabetes Drugs Have Different Advantages, Study Says
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
More New Drugs a Bad Fit With Grapefruit, Study Finds
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating ... many ways they remain in the eye of the beholder, according to experts who ... of The American Journal of Managed Care. For the full issue, click here ...
(Date:6/26/2016)... ... June 26, 2016 , ... PawPaws brand pet supplements ... was developed to enhance the health of felines. The formula is all-natural and is ... herbs in the PawPaws Cat Kidney Support Supplement Soft Chews are Astragalus ...
(Date:6/25/2016)... D.C. (PRWEB) , ... June 25, 2016 , ... ... discuss health policy issues and applications at AcademyHealth’s Annual Research Meeting June 26-28, ... their work on several important health care topics including advance care planning, healthcare ...
(Date:6/25/2016)... ... 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users can easily ... of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn pictures ... . Simply select a ProHand generator and drag it above media or text in ...
(Date:6/25/2016)... Oklahoma City, Oklahoma (PRWEB) , ... June 25, ... ... to helping both athletes and non-athletes recover from injury. Recently, he has implemented ... for the Oklahoma City area —Johnson is one of the first doctors to ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016   Bay ... Rehabilitation Network,s Dean Center for Tick Borne ... Medicine and Rehabilitation, MIT Hacking Medicine, University of ... Innovation, today announced the five finalists of ... Lyme disease.  More than 100 scientists, clinicians, researchers, ...
(Date:6/24/2016)... , June 24, 2016 ... the "Structural Electronics 2015-2025: Applications, Technologies, Forecasts" ... In-Mold Electronics, Smart Skin, Structural ... Structural electronics involves electronic and/or ... protective structures, replacing dumb structures such as vehicle ...
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical Systems ... "Company"), which develops, markets and sells medical devices and ... , signed a strategic cooperation agreement with Hongyuan Supply ... Supply Chain") on June 20, 2016, to develop Dehaier,s ... strategic cooperation agreement, Dehaier will leverage Hongyuan Supply Chain,s ...
Breaking Medicine Technology: