Fatty food helps drug absorption

Taking medicines, particularly cancer drugs, with certain foods could make them more effective and therefore reduce costs, reported news sources including BBC News, The Daily Telegraph and the Daily Mail .

This proposal was based on an editorial about a study that found that absorption of the breast cancer drug lapatinib (Tykerb) was increased by 325% with fatty food and by 167% with low-fat food compared with taking the medicine on an empty stomach. The Daily Mail and the Telegraph also reported that taking the drug with grapefruit juice would also increase drug absorption.

The Telegraph reported that if smaller doses could be given the monthly cost of the drug could be reduced from £1,424 to £285.

The Daily Mail did note that the authors of the study cautioned against patients reducing their doses before more research has been conducted.

Though the original research has not been published in full, the report of it in the editorial highlights some limitations:

• The study did not appear to assess whether lower doses of the drug taken with food have the same benefits and harms as taking the recommended higher dose while fasting.
• The study only assessed the absorption rates when combined with different types of food, not grapefruit juice. This means we can’t draw conclusions about the effects of taking the drug with grapefruit juice.
• The findings relate to laptinib only; taking other drugs with high-fat foods will not necessarily have the same effects on absorption.

Where did the story come from?

The newspaper story is based on an editorial from the Journal of Clinical Oncology and jointly written by Professor Mark Ratain and Assistant Professor Ezra Cohen of the University of Chicago’s Department of Medicine.

The editorial discusses the findings of a study looking at the body’s absorption of lapatinib. It was not clear whether the authors of the editorial were also involved in this study. The study was presented at a conference in 2007, and has not yet been published in full. This assessment is based on the information provided in the editorial.

What kind of scientific study was this?

The study was a randomised crossover trial, where people took 1,500 milligrams of lapatinib with low-fat food, high-fat food, or while fasting, in a random order, and the levels of laptinib in the blood measured over time under these different conditions. No further details about the study were presented in the editorial.

What were the results of the study?

The amount of lapatinib that was absorbed into the blood increased by 167% if the drug was taken with low-fat food, and by 325% if it was taken with high-fat food, compared with taking the medicine on an empty stomach.

What do the researchers say?

The authors of the editorial suggest that, based on the results of this study, monthly drug costs could potentially be reduced by 60% by taking the drug with food, because the dose needed would be reduced. They also raise the possibility that if the drug was taken with food, this may reduce side effects caused by the non-absorbed drug, for example, diarrhoea. The authors further suggest that absorption of the drug could also be increased if it was taken with grapefruit juice. However, the authors “strongly recommend” that studies need to be carried out to test these hypotheses, before any changes in drug dose recommendations are made.

What does the NHS Knowledge Service make of this study?

Although the study itself provided interesting findings about how to increase absorption of lapatinib, we should bear certain limitations in mind, many of which are mentioned by the editorial’s authors.

• The study looks only at how taking laptinib with food affects its absorption into the blood stream. It did not assess whether lower doses of the drug taken with food have the same benefits and harms as taking the recommended higher dose whilst fasting.
• Only the effects of different types of food on absorption were assessed. The effect of taking the drug with grapefruit juice was not tested.
• These findings of this study relate to laptinib only; taking other drugs with high-fat foods will not necessarily have the same effects on absorption.

The editorial is based on the authors’ opinions, and suggests possible ways of reducing drug costs by taking advantage of drug-food interactions. It provides information on which to design further studies and these hypotheses need to be tested before changing how the drug is given in practice.