- By James Gallagher
- Health and Science Correspondent, BBC News
We have the technology to usher in a new era of medicine by precisely matching drugs to people’s genetic code, says a major report.
Some drugs are completely ineffective or become fatal due to subtle differences in how our bodies work.
The British Pharmacological Society and the Royal College of Physicians claim that a genetic test can predict the effectiveness of drugs in the body.
These tests could be available at the NHS, the National Health Service, next year.
Your genetic code or DNA is an instruction manual for how your body works. The field of matching drugs to your DNA is known as pharmacogenomics.
It could have helped Liverpool’s Jane Burns, who lost two-thirds of her skin when she reacted badly to a new epilepsy drug.
She was put on carbamazepine when she was 19. Two weeks later, she developed a rash and her parents took her to the emergency room when she had a high fever and started hallucinating.
The skin lesions started the next morning. Jane told the BBC: “I remember waking up and I was covered in blisters, it looked like I had stepped out of a horror movie, it was like I had been on fire.”
His epilepsy drug caused Stevens-Johnson syndrome, which affects the skin and is much more likely to occur in people born with specific mutations in their genetic code.
Burns says he was “tremendously, tremendously lucky,” and says he is in favor of pharmacogenomic testing.
“If it saves your life, then that’s a fantastic thing,” she says.
Almost everyone is affected
Jane’s experience may seem rare, but Professor Mark Caulfield, president of the British Pharmacological Society, said that “99.5% of us have at least one change in our genome which, if they come across the wrong drug either won’t work or actually cause harm.”
- Codeine does not provide pain relief for over five million people in the UK. Their genetic code does not contain the instructions for making the enzyme that breaks down codeine into morphine, and without it the drug is ineffective.
- One in 500 people’s genetic code puts them at a higher risk of losing their hearing if they take gentamicin, which is an antibiotic. Pharmacogenomics is already used for some drugs. In the past, 5-7% of people reacted badly to Abacavir, an HIV drug, and some died from it. By testing people’s DNA before prescribing the drug, the risk is now zero.
Scientists have looked at the 100 most prescribed drugs in the UK. Their report says we already have the technology to deploy genetic tests to guide the use of 40 of them.
Genetic analysis would cost around £100 (around 78,000 CFA francs) and could be done from a blood or saliva sample.
Initially, the objective is to carry out the test when one of the 40 drugs is prescribed. In the long term, the ambition is to carry out the test well before, possibly at birth if genetic tests are carried out on newborns, or as part of a routine examination in the fifties.
“A new personalized, modern care system”
“We need to move away from the ‘one drug and one dose for all’ approach in favor of a more personalized approach, where patients receive the right drug at the right dose, in order to improve drug efficacy and safety” , says Professor Sir Munir Pirmohamed, of the University of Liverpool.
“What we’re doing is really moving towards a new era of medicine, because we’re all individuals and we all vary in how we respond to medications,” he explains.
Sir Munir Pirmohamed said that as you get older and are prescribed more and more drugs, there is a 70% chance that by the age of 70 you will be taking at least one drug that is influenced by your genetic makeup.
Lord David Prior, the chairman of NHS England, argues that “it will revolutionize medicine”.
He states that pharmacogenomics “is the future” and “can now help us build a new, personalized, modern healthcare system…”