One off test could prevent death and suffering (Image: Getty)
The NHS could slash costs by up to £700 million a year and prevent thousands of hospital admissions by using DNA testing to personalise prescriptions.
Every year, thousands of people suffer severe reactions to medicines—some with fatal consequences. Research by scientists at the University of Liverpool has revealed that treating these side effects is costing the NHS £2.2 billion annually in England alone.
Now, groundbreaking research suggests a simple DNA test could cut adverse drug reactions by nearly a third, dramatically reducing hospital admissions and suffering.
The Liverpool team, working with experts from the University of Bangor and the Office of Health Economics, is set to publish its findings on how much such genetic testing will save the economy later this summer.
Leading the research is Professor Sir Munir Pirmohamed, Chair in Medicine at Liverpool University and NHS Chair of Pharmacogenetics, who says these tests could revolutionise treatment:
“Based on our preliminary data, we estimate that DNA testing could reduce adverse drug reactions by 30%, saving the NHS up to £700 million a year. But beyond the financial impact, the real benefit is reducing patient suffering. DNA testing can improve lives by ensuring patients receive the right medicine at the right dose.”
Prof Pirmohamed is now calling for the NHS to roll out genetic testing nationwide, making it routine practice for prescribing. He suggests storing patients’ genetic data on smartphones and linking it to their medical records to ensure they receive the most effective medication with the fewest side effects.
These one-time tests, costing between £50 and £250, involve a simple blood sample or cheek swab and can identify genetic markers that influence drug response. There are already around 100 available tests, covering medications for heart disease, high cholesterol, depression, cancer, schizophrenia, pain relief, and epilepsy.
This pharmacogenetic testing removes the guesswork from prescribing, ensuring patients receive drugs tailored to their genetic makeup.
University of Liverpool – groundbreaking research (Image: Getty)
Prof Pirmohamed said: “Adverse drug reactions are a spectrum in terms of severity. Some patients experience mild dizziness or nausea, leading them to stop taking their medication, which then worsens their condition. Others suffer severe reactions—some thyroid and anti-cancer drugs can deplete bone marrow, and epilepsy drugs can cause life-threatening skin conditions requiring intensive care. Even antidepressants can lead to side effects ,some of which may be preventable by genetic testing.”
One example is the CYP2D6 gene, which affects how people metabolise codeine. Some individuals process it too fast, which can lead to side effects, while others cannot break it down which means it does not lead to any pain relief.
Similarly, clopidogrel, a widely used blood thinner, is ineffective in up to 50 percent of patients due to genetic variants—leaving them at risk of heart attacks and strokes. Genetic testing could identify these cases and allow doctors to prescribe a safer, more effective alternative.
DNA test from blood or cheek swabs may be used (Image: Getty)
Despite the clear benefits, DNA testing is not yet widely available in the NHS. Prof Pirmohamed is urging the government to expand access and train doctors in using these tests effectively. Earlier this year the University of Liverpool launched a new project to study how the variation of the human genome affects the effectiveness and safety of medicines – known as the Centre for Excellence in Regulatory Science and Innovation in Pharmacogenomics project. The work is backed by the government’s innovations agency – Innovate UK and regulatory agency – The Medicines and Healthcare products Regulatory Agency (MHRA), the Office for Life Sciences, and the Medical Research Council.
“The NHS has a huge opportunity to lead the way in precision medicine by adopting pharmacogenomic testing at scale,” Prof Pirmohamed said.
Other countries are already ahead. In the Netherlands patients are routinely tested for genetic markers before receiving leukaemia and autoimmune disease treatments, reducing harmful side effects. In Spain, similar screening is offered before prescribing certain medicines.