June Hughes I first heard of this about ten years ago, when I was overseeing the care of a relative with a damaged heart. Apparently, it has caused some serious problems, largely in older people.
Author: Mark Bloom, HealthDay Reporter Copyright © 2005 ScoutNews LLC. All rights reserved.
"So why is a grapefruit a two-faced fruit? Whatâs in a grapefruit thatâs not in an orange, apple or cranberry, or other juices? In 1993, the Canadian group and another from the University of Michigan group homed in on an important enzyme, CYP 3A4, in the wall of the intestine. It was known that when something interferes with the breakdown of medicines by this enzyme, blood levels of a drug can rise inappropriately.
"The responsible compound in a grapefruit has not been isolated. Some biochemists believe that the culprit may be a bioflavonoid, perhaps whatever it is that gives grapefruit its unique bittersweet taste. The only other fruit that shares the ăgrapefruit effectä appears to be Seville oranges, used primarily for making marmalade.
"The ăgrapefruit effectä can be strong. A glbutt of grapefruit juice, or a half grapefruit, consumed even 24 hours before or after taking certain drugs, perhaps as long as 48 hours, can interact with certain drugs. For some people, though, this may not be so. It seems to depends on the amount of CYP 3A4 in the digestive tract, which varies greatly from person to person, and there is no simple test for it. Older people tend to be more sensitive to the grapefruit effect, and too much active drug in the blood stream can be dangerous for them.
"Sixteen years ago the original drug found to interact with grapefruit was a single member of the clbutt of drugs known calcium channel blockers, then and now a group of agents that are important for blood pressure control and other conditions.
PheasantsFirst decide if you want to hang it or cook it fresh. Fresh is fine (and my preference) but after two or three days the flesh will toughen and...
"Since then several other well-known drugs in this clbutt have also been labeled as sensitive to mixing with grapefruits. In addition, widely prescribed drugs for cholesterol lowering had been added to the list ÷ well-known drugs such as Lipitor, Mevacor, and Zocor (but not Pravachol). Also bearing ăgrapefruit-effectä warnings are certain anti-anxiety and sleeping pills, drugs to prevent organ-rejection after transplants, agents for HIV-AIDS, at least one epilepsy drug, some birth-control pills, certain drugs for heart rhythm disturbances, blood-thinners, some antibiotics, and even erection-enhancing Viagra."
SOURCES: Kristine Cuthrell, R.D., research nutritionist and project coordinator, Cancer Research Center of Hawaii, University of Hawaii, Honolulu; Ken Fujioka, M.D., Nutrition and Metabolism, Scripps Clinic, San Diego, Ca.; Julie Upton, R.D., American Dietetic buttociation, spokeswoman; August 24-25, 2004 presentation, American Chemical Society 228th national meeting, Philadelphia Amy Karch, R.N., M.S., clinical buttociate 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; Drug Consumer, FDA, August 2004
