Genes can affect a person's response to statins, drugs used to lower blood cholesterol levels, say US researchers. Researchers at the Brigham and Women's Hospital in Boston say their study shows that knowledge about the interaction between genes and drugs is growing 'in leaps and bounds'. Their findings, published in the Journal of the American Medical Association, show that particular variations in a single gene are linked to a reduced response to the drug pravastatin.
Many scientists predict that pharmacogenetics - the use of genetic tests to match medicines to a person's genetic make-up - will revolutionise health care in the future. However, only a handful of the genetic variations linked to adverse reactions or a reduced response to a particular drug have so far been identified. The latest study looked at 1,563 people taking pravastatin, prescribed to lower cholesterol levels. Statins work by blocking the action of a protein called HMG-CoA reductase gene, which in turn lowers levels of both total and so-called 'bad' low density lipoprotein (LDL) cholesterol. The scientists found that people with variations in the HMG-CoA reductase gene had a 22 per cent smaller reduction in total cholesterol, and a 19 per cent smaller reduction in LDL cholesterol, compared to those who did not have the gene variants.
Around seven per cent of the study participants had the genetic variations associated with a reduced response to pravastatin. Team leader Paul Ridker is not surprised by the findings, saying that 'we've known for some time that some patients get a greater reduction than others'. But the results do not call for any major change in treating patients, he says, adding that 'it could well be that just a higher dose will overcome this problem'. According to Susanne Haga, who wrote an editorial accompanying the report, 'information on how genetic variation affects drug efficacy and drug safety will become a basic part of drug development'. But she added that, at the moment, 'the commercial ability to test for these variations is not available'.