From: [C upi] at [clari.net] (UPI)
Newsgroups: clari.biz.industry.health.pharma,clari.news.alcohol+drugs
Subject: Don't mix drugs and grapefruit juice
Organization: Copyright 1996 by United Press International
Date: Thu, 29 Aug 1996 12:30:45 PDT
                                         
                          UPI Science News      
        ORLANDO, Florida, Aug. 29 (UPI) -- Grapefruit juice and prescription  
drugs don't mix, researchers warned Thursday. 
        A substance in grapefruit juice, but not in orange juice, can make  
the body absorb too much or too little of common drugs, said researchers 
at the national meeting of the American Chemical Society in Orlando, 
Florida. However, the effect has potential benefits -- if researchers can 
harness them. 
        The amount of calcium channel blockers, drugs used to treat heart  
patients, can triple in the blood stream leading to a greater than 
expected dip in blood pressure if someone washes down the pills with 
grapefruit juice, said Barbara Ameer, a pharmacology consultant in 
Princeton, New Jersey. 
        Other drugs that can react with grapefruit juice include estrogen-  
type hormones, used to ease menopause, and the popular antihistamine 
called terfenadine, or Seldane, prescribed for allergy sufferers. 
        Ameer and colleagues reported that researchers were even able to see  
a difference in electrocardiograms between patients that did, and did 
not, drink grapefruit juice when taking Seldane. Heart rhythm 
abnormalities were no longer detectable when people separated their 
pills and grapefruit juice by more than two hours. 
        Seldane's makers, however, said they have been unable to pin down a  
grapefruit interaction although they have received anecdotal reports. 
``There is no causal link based on available data,'' said Charles Rouse, 
spokesman for Hoechst Marion Rousel in Kansas City, Missouri. ``There 
may have been other risk factors. We're not sure it's clinically 
significant.'' 
        Gay Yee from the University of Florida's College of Pharmacy in  
Gainesville, has proposed a way to take advantage of the grapefruit 
effect. Organ transplant patients who take cyclosporine to keep their 
bodies from rejecting the transplanted tissue often take other drugs to 
enhance absorption. Part of the motive for reducing the dosage needed 
for cyclosporine is cost, since insurance companies often do not cover 
the drug, leaving patients to pay between $5,000 and $10,000 a year for 
the rest of their lives. 
        The antifungal drug ketoconazole can reduce the need for cyclosporine  
by 80 percent, ``but we'd much rather have them take something natural, 
like grapefruit juice, if we can achieve the same effect,'' Yee said. 
        In a study of 14 people, Yee and colleagues have been able to use  
grapefruit juice to enhance the concentrations of cyclosporine by an 
average of 40 percent. Yee said, ``We're continuing the study to 
determine the optimal dose of grapefruit juice.''