Possible interactions between drugs and grapefruit juice

[Guest guest]

Dear Friends,

 

Here is an article of possible interest to those of you who are

taking medications and grapefruit juice, about possible interactions.

 

Swamy

 

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Update: Grapefruit Juice-Drug Interactions Still Pose Risks

 

Nursing journal sends out renewed warning on potentially dangerous

consequences

 

By Randy Dotinga

HealthDay Reporter

 

 

FRIDAY, Jan. 21 (HealthDayNews) -- American nurses are getting a

reminder that grapefruit juice is notable for more than its ability

to make you pucker: In some cases, it can spell big trouble for

people who take certain prescription drugs.

 

Grapefruit juice can interfere with the body's absorption of some two

dozen medications, from the cholesterol-lowering drug Lipitor to

erectile-enhancing Viagra. While warnings appear in the information

given to patients, they're easy to miss, said Amy Karch, a clinical

associate professor of nursing at the University of Rochester Medical

Center who wrote an article warning about the risks in last month's

issue of the American Journal of Nursing.

 

" A lot of people rely on their health-care providers to alert them to

anything that would be really important, but it is so hard to keep up

with all of the constantly changing drug information that there

probably are doctors who are not aware of the possibility, " Karch

said.

 

But don't rush to throw out your carton of grapefruit juice just yet.

The fruit itself has gained a reputation as a possible fat-fighter,

and one doctor speaking for fruit growers said patients shouldn't

overreact when they hear about potential drug interactions.

 

The risks of grapefruit juice are not new, but many patients don't

seem to be aware of it, Karch said.

 

According to researchers, grapefruit juice affects the production of

enzymes in the liver, which is part of the body's filtration system.

The liver also metabolizes drugs and, in some cases, the presence of

grapefruit juice can boost or diminish the concentration of a drug in

the body, strengthening or weakening its effects.

 

For example, it's conceivable that grapefruit juice could boost the

effectiveness of a blood pressure-lowering medication, said Dr. Ken

Fujioka, director of nutrition and metabolic research at Scripps

Clinic in San Diego. " If you're driving blood pressure too low,

patients can get into problems -- they can get lightheaded and pass

out. "

 

In her article, Karch tells the story of a 59-year-old retired

government auditor who had several risk factors for heart disease,

including obesity and high cholesterol. His doctor put him on

Lipitor. Meanwhile, the man traveled to his winter home in Florida,

and began drinking several glasses of fresh grapefruit juice a day.

 

The man developed serious kidney problems, and a nurse realized the

grapefruit juice may have caused them by boosting the levels of

Lipitor in his system. The patient was told to try other medications.

 

A long list of popular drugs interact with grapefruit juice,

including AIDS medications, the blood thinner Coumadin (warfarin),

the antibiotic erythromycin, and the hormones estrogen and

testosterone.

 

" The effect is not just immediate, it may last five, six, seven or 12

hours, " Fujioka said. " You may have some differences in terms of

where the juice is reconstituted, frozen or fresh. There could be

huge variations in the effect it has on drug levels. "

 

The good news is that most drugs don't appear to interact with

grapefruit juice, and there are often alternatives to those that do,

said Dr. Hartmut Derendorf, a professor at the University of

Florida's College of Pharmacy, in a statement provided by the Florida

Department of Citrus.

 

And grapefruit itself may have its own health benefits. Fujioka

reported last year that people who ate one-and-a-half grapefruit a

day lost more weight than those who consumed grapefruit juice,

grapefruit extract or a placebo. " It may reasonable to be looking at

grapefruit itself as a better alternative " to the juice, he said.

 

More information

 

Public Citizen's Health Research Group has more about potential

grapefruit juice interactions (www.citizen.org ).

 

 

 

SOURCES: Amy Karch, R.N., M.S., clinical associate professor,

nursing, University of Rochester, N.Y.; Ken Fujioka, M.D., director,

nutrition and metabolic research, Scripps Clinic, San Diego; December

2004 American Journal of Nursing

 

2005 ScoutNews LLC. All rights reserved.

 

Last updated 1/21/2005.

 

This article can be accessed directly at:

http://www.healthscout.com/news/1/523552/main.html