Why do some people develop a RASH or a headache or are overcome with nausea when they take a certain drug but others suffer no ill effects? It’s all in your genes, says GP Dr Andrew Winnington, who has developed a platform that can show your probable reaction to nearly 800 common medicines.
He says harmful drug reactions, often seen in general practice and emergency departments, are highly underreported.
Bay of Plenty clinical pharmacist Pauline McQuoid agrees. Conducting her own research, she found medicine-related harm, including errors by doctors, pharmacists and nurses as well as bad reactions to drugs, kills more than double the numbers claimed by road accidents and suicide combined – about 2300 people a year. Thousands more are left with life-threatening or permanent injury.
But no one is talking about it and the extent of such harm is largely hidden. The impact of pharmacogenomics – using your genetic information to identify which medicines may help you and which may cause a harmful reaction – will be “huge” and work has already started in various parts of the country, she says.
Winnington’s XY Leap platform, 10 years in development, is not yet available for public consumption. After more testing, it will become available to patients nationwide through community-based outlets such as a blood lab or pharmacy by the end of the year, he says. The cost: about $700. Patients’ genetic material – either by blood sample or saliva test – will be sent to a lab where the DNA is extracted and then batch-processed to deliver 800,000 pieces of data for each individual. This can then be processed through Winnington’s analytics software and a 200-page personalised report produced.
As well as testing against 785 medications, Winnington’s medical “omics” platform can also provide guidance on 20 diet plans and 50 nutriceuticals, 20 exercise programmes, 40 plants and fungi.
Such a test may show, for example, an increased risk of severe cutaneous (skin) adverse reactions if you take allopurinol for gout, or an increased risk of vitamin D deficiency, a greater risk of side effects from certain antidepressants or a warning that a painkiller might not prove effective.
A large European study, published in the Lancet last year, showed genetic analysis can reduce serious reactions to drugs by an average 30%. The three-year study covered nearly 7000 genotyped patients looking specifically at 12 genes relevant to drug metabolism and side effects.
But it’s not just about side effects; drug efficacy is also at play. Research conducted from 2008-10 indicated many Māori patients on antidepressants (metabolised by the gene CYP2C19) needed to be prescribed half their initial dose to prevent adverse drug reactions such as increased suicidality.
Winnington is scathing of genetic testing websites such as 23andMe, which he says take your data and give you “fluff”.
“There’s a market for [this] aggregated data – to insurance companies, pharma – that whole murky backend which is essentially running healthcare,” he says.
“People don’t know how dangerous their data is – it tells you how you’re going to die – not 100%, but it tells you your disease susceptibility.”
He’s equally trenchant about where our healthcare system is letting us down.
“The whole idea of precision medicine is that you live well for longer but that’s not the [medical] system. We’re in a system where it’s better if you’re sick. It’s a treatment model rather than a preventive one.”
XY Leap is not a tool for diagnosing genetic conditions. It combines individual genetic data with evidence-based recommendations from the US Food and Drug Administration and dosing guidelines from international pharmacogenomic organisations.
For drugs and herbal medicines without published guidelines or recommendations, the platform provides a pharmacogenomic analysis for individual patients.
For safety reasons, these results can only be accessed through a GP or nurse who should be able to explain what they mean.
A red flag over a medicine may not mean you should stop taking it but possibly a lower dosage is advised.
Winnington also emphasises the safety of his platform. No data is kept online, so sovereignty over personal genetic information is preserved.
Read more on this story: Precision Medicine: Using genetic information to treat illnesses is touted as medicine’s holy grail and the Scottish whaler who has bequeathed his thousands of Kiwi descendants a potential genetic timebomb.
