Breast cancer drug works better on a full stomach

Jul 17 2007

Experts in the United States say that eating the right food with certain medications could improve the effectiveness of drugs and also reduce the cost of treating patients.

The oncologists from the University of Chicago suggest that taking a breast cancer drug with fatty food, rather than on an empty stomach, boosts absorption of the drug and means patients could take lower doses, which would reduce costs.

They found that taking the breast cancer drug lapatinib at the same time as a fatty meal may make it work at least three times as well and when grapefruit juice accompanies the meal the researchers say the pills could be five times more effective than normal by aiding absorption.

The researchers say however that further tests are needed and that patients should not alter how they take their cancer drugs.

They suspect a better understanding of the relationship between common drugs such as statins and for example grapefruit juice could possibly cut down drug costs.

In the past experts have warned of the potential dangers of interactions between food and drugs which can render drugs becoming toxic, or less effective.

Professors Mark Ratain and Ezra Cohen say they have found that taking the breast cancer drug lapatinib (TYKERB) with food, rather than on an empty stomach as suggested on the label, increased the availability of the drug in the body by 167%, meaning the drug could work more effectively; taking it with a meal rich in fat boosted levels by 325%.

The researchers say their findings about the interactions between foods and anti-cancer drugs could be exploited to help decrease costs and increase the benefits from such drugs.

Professor Ratain says by simply changing the timing and taking lapatinib with a meal instead of on an empty stomach only 40% of the drug is needed.

Grapefruit is known to boost absorption of certain drugs and Professor Ratain says drinking grapefruit juice, which is known to increase the rate at which some drugs enter the blood stream could increase these savings even further.

Ratain also suggests that eating such "value meals" at the same time as taking drugs could have other benefits too; a major toxicity associated with lapatinib is diarrhoea, which is thought to be caused by some of the drug being unabsorbed, therefore taking lower doses with food to boost its absorption should help reduce this side-effects.

He says that one 250mg lapatinib pill accompanied by food and a glass of grapefruit juice may yield plasma concentrations comparable to five pills on an empty stomach.

The authors caution against patients experimenting themselves and say more research to assess the effects of drug-combinations on patients.

They are in fact currently conducting a study testing the effect of combining a drug with grapefruit juice.

The Medicines and Healthcare Products Regulatory Agency says any new recommendations about drug dosages need to be backed up by evidence and full testing through clinical trials.

The research is published in the Journal of Clinical Oncology.