Grapefruit juice boosts drug's anti-cancer effects

Sirolimus, a drug typically used by transplant patients to prevent rejection, has been found in previous studies to have anti-cancer properties as well. While its not currently used to treat cancer, there may be a way to give those properties a boost, and make the drug a feasible option for cancer patients by adding some grapefruit juice.

A new study from the University of Chicago Medicine revealed patients taking sirolimus receive more of its anti-cancer benefits if they drink a glass of grapefruit juice every day along with the drug. The drug-juice combination was so effective that patients who drank grapefruit juice obtained three times as many benefits than those who took the drug alone.

This is also interesting because of grapefruits dangerous interaction with some prescription medications, namely ones that treat high blood pressure and heart conditions.

Researchers had discovered sirolimus potential anti-cancer properties from previous research.

Its a drug that was discovered in the 70s, Dr. Ezra Cohen, a cancer specialist at the University of Chicago Medicine and the studys lead author, told FoxNews.com. It was clearly shown to have anti-cancer effects and anti-neoplastic effects, but it hadnt been developed for cancer extensively because the patent ran out. There wasnt a lot of commercial interest to develop sirolimus, so it sort of was pushed aside for a while. Eventually, sirolimus was indeed approved, but for people who got organ transplants to prevent rejection.

Cohen and his team study how food consumption can either help or hurt the effectiveness of drugs used for cancer therapy. They got the idea to test grapefruit juice from another previous study around two decades ago.

Investigators were doing a study on alcohols effect on a certain heart drug, Cohen said. And to mask the taste of alcohol, they used grapefruit juice. What they ended up finding out was that the grapefruit juice increased the blood levels of the drug.

Putting the two studies together, the scientists enrolled 138 patients with incurable cancer, splitting them into three groups those who received only sirolimus, sirolimus and ketoconazole (a compound that slows drug metabolism), and sirolimus and grapefruit juice. They hoped these different combinations would boost the drugs absorptive power.

One of the issues with sirolimus is that it has very poor bioavailability, meaning only 14 percent gets absorbed when you take the pill, Cohen said. Thats why the company that manufacturers sirolimus actually created an intravenous analog of the drug, because of the availability issue. So we thought, Why dont we try to modify the metabolism of sirolimus by using a ketoconazole or using grapefruit juice. If we can reduce even some of the side effects associated with the drug and develop a combination, that could be effective.

At first, the participants were given very low doses of sirolimus, but the amounts were slowly increased as time went on in order to determine how much of the drug was need to reach goal levels and maximize its efficacy.

The rest is here:
Grapefruit juice boosts drug's anti-cancer effects