Corporate Banner
Satellite Banner
Food & Beverage Analysis
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Grapefruit Juice Lets Patients Take Lower Dose of Cancer Drug

Published: Thursday, August 09, 2012
Last Updated: Thursday, August 09, 2012
Bookmark and Share
First cancer study to harness drug-food interaction.

A daily glass of grapefruit juice lets patients derive the same benefits from an anti-cancer drug as they would get from more than three times as much of the drug by itself, according to a new clinical trial.

The combination could help patients avoid side effects associated with high doses of the drug and reduce the cost of the medication.

Researchers at the University of Chicago Medicine study the effects that foods can have on the uptake and elimination of drugs used for cancer treatment.

In a study published in August in Clinical Cancer Research, they show that eight ounces a day of grapefruit juice can slow the body’s metabolism of a drug called sirolimus, which has been approved for transplant patients but may also help many people with cancer.

Patients who drank eight ounces a day of grapefruit juice increased their sirolimus levels by 350 percent.

A drug called ketoconazole that also slows drug metabolism increased sirolimus levels by 500 percent.

“Grapefruit juice, and drugs with a similar mechanism, can significantly increase blood levels of many drugs,” said study director Ezra Cohen, a cancer specialist at the University of Chicago Medicine, “but this has long been considered an overdose hazard. Instead, we wanted to see if grapefruit juice can be used in a controlled fashion to increase the availability and efficacy of sirolimus.”

First study to harness drug-food interaction
Grapefruit juice’s pharmaceutical prowess stems from its ability to inhibit enzymes in the intestine that break down sirolimus and several other drugs.

The effect begins within a few hours of what the researchers refer to as “grapefruit juice administration.” It wears off gradually over a few days.

Cohen and colleagues organized three simultaneous phase-1 trials of sirolimus. Patients received only sirolimus, sirolimus plus ketoconazole, or sirolimus plus grapefruit juice. They enrolled 138 patients with incurable cancer and no known effective therapy.

The first patients started with very low sirolimus doses, but the amounts increased as the study went on, to see how much of the drug was required in each setting to reach targeted levels, so that patients got the greatest anti-cancer effect with the least side effects.

The optimal cancer-fighting dose for those taking sirolimus was about 90 mg per week.

At doses above 45 mg, however, the drug caused serious gastrointestinal problems, such as nausea and diarrhea, so patients taking sirolimus alone switched to 45 mg twice a week.

The optimal doses for the other two groups were much lower. Patients taking sirolimus plus ketoconazole needed only 16 mg per week to maintain the same levels of drug in the blood.

Those taking sirolimus plus grapefruit juice needed between 25 and 35 mg of sirolimus per week.

“This is the first cancer study to harness this drug-food interaction,” the authors note. This study built upon an early clinical trial, which found grapefruit juice boosted anti-cancer effects.

Numerous benefits of grapefruit juice
No patients in the study had a complete response, but about 30 percent of patients in the three trials had stable disease, meaning a period when their cancers did not advance.

One patient receiving grapefruit juice had a partial response-significant tumor shrinkage-that lasted for more than three years.

Although ketoconazole produced a slightly stronger drug-retention effect, grapefruit juice has the advantage that it is non-toxic, with no risk of overdose.

“Therefore,” the authors wrote, “we have at our disposal an agent that can markedly increase bioavailability (in this study by approximately 350 percent) and, critically in the current environment, decrease prescription drug spending on many agents metabolized by P450 enzymes.”

Sirolimus was the first of a series of drugs, known as mTOR inhibitors, that were developed to prevent rejection of transplanted organs but that also have anti-cancer effects.

As the first of its class, it was also the first to come off patent, making it less costly. “Further cost savings,” the authors suggest, could be realized “by combining the drug with agents that inhibit its metabolism.”

Because different people produce varied amounts of the enzymes that break down sirolimus, the effect of grapefruit juice can vary, but tests of enzyme levels may be able to predict how an individual patient will respond.

“The variation in potency of the grapefruit juice itself may be far greater than the variation in the enzymes that break down sirolimus,” Cohen said.

An early version of the study used canned grapefruit juice, generously donated by a Chicago-based grocery chain. But tests of the product found it lacked the active ingredients. So the researchers shifted to a frozen concentrate product supplied by the Florida Department of Citrus.

This study was supported by the National Institutes of Health-and not by a pharmaceutical company.

Dose-finding studies are “not necessarily profitable” for drug makers, the authors note, especially if the study results in lower recommended doses after the drug has been approved and priced.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,400+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Gut Bacteria that Protect Against Food Allergies Identified
Common gut bacteria prevent sensitization to allergens in a mouse model for peanut allergy, paving the way for probiotic therapies to treat food allergies.
Wednesday, August 27, 2014
Researchers Identify ‘Fat Gene’ Associated with Obesity
Mutations within the gene FTO have been implicated as the strongest genetic determinant of obesity risk in humans, but the mechanism behind this link remained unknown.
Monday, March 17, 2014
Manipulating the Microbiome Could help Manage Weight
UChicago researchers team was able to unravel some of the mechanisms that regulate this weight gain.
Thursday, August 30, 2012
Scientific News
Pesticide Found in 70 Percent of Massachusetts’ Honey Samples
New Harvard University study says that the pesticide commonly found in honey samples is implicated in Colony Collapse Disorder.
Printed "Smart Cap" Detects Spoiled Food
It might not be long before consumers can just hit “print” to create an electronic circuit or wireless sensor in the comfort of their homes.
Red Wine Antioxidant May Provide New Cancer Therapy Options
Resveratrol and quercetin, two polyphenols that have been widely studied for their health properties, may soon become the basis of an important new advance in cancer treatment,
New Research will Show How the Environment Could Change the Way We Eat
A new study funded by the Wellcome Trust will investigate how environmental changes over the next 20-30 years may impact the way we eat, in the UK and worldwide.
Blue LEDs Can be Used to Preserve Food
Blue light emitting diodes (LEDs) have strong antibacterial effect on major foodborne pathogens and can be used as a chemical-free food preservation method, a new study has found.
FDA Declares Trans Fatty Acids Unsafe for Consumption
TFAs are widely recognized as the most harmful fat with regard to causing cardiovascular disease (CVD).
Fat, Sugar Cause Bacterial Changes that may Relate to Loss of Cognitive Function
A study has indicated that both a high-fat and a high-sugar diet, compared to a normal diet, cause changes in gut bacteria that appear related to a significant loss of "cognitive flexibility," or the power to adapt and adjust to changing situations.
How Anthrax Spores Grow in Cultured Human Tissues
New findings to help predict risk and outcomes of anthrax attacks.
Food Research at the Microscale
Thermal stage microscopy allows food science microscopists to analyze samples under a range of conditions.
Chocolate, Chocolate, It's Good For Your Heart
Here's a sweet notion: Eat a little chocolate each day and you could be doing your heart a favor.
SELECTBIO

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!