No more ‘one size fits all’

March 25, 2018
Orla Green
Use of biomarkers

Personalising drug therapy works by identifying certain genetic traits, or ‘biomarkers’, which determine how an individual will respond to specific drugs. In some cases, the presence of a particular biomarker represents a poor response to a drug type, which would influence drug choice for patients. Recent studies have identified genes which cause a poor response to a popular anticoagulant, Clopidogrel, which is currently prescribed to over 30 million patients in the US and over 5 million in the UK. The presence of the ‘poor response’ gene means thousands of patients may be experiencing a reduced benefit of the drug, and so are unknowingly at risk of blood clotting. If clinicians were to test patients for their response to this drug prior to prescription, thousands of patients would benefit from a more tailored and effective heart treatment.

Genetic basis of metabolism

Similar studies have shown that genetic traits additionally influence the metabolism of certain drugs, meaning how quickly they are broken down by your body and what effective dosage you require. One example of this is Warfarin, a common and effective treatment to prevent blood clots, which was prescribed to over 11 million people in the UK in 2014 alone. However, the NHS states that the dosage required between individuals varies by up to 40 fold, due to varying drug metabolism rates. The current ‘trial and error’ technique used by the NHS to prescribe this drug means patients often suffer unnecessary side effects. By identifying certain genetic traits associated with poor warfarin metabolism, clinicians would be able to more accurately prescribe the accurate dosage first time around. This creates a huge and exciting potential for new personalised therapies to transform the medical approach to cardiovascular disease prevention and treatment.

The NHS states that the dosage of Warfarin required between individuals varies by up to 40 fold due to varying drug metabolism rates

Predicting drug response

Interestingly, the genes which determine your response to certain medications often run in families, having been inherited from your parents. This means that identifying certain genetic traits you possess which influence drug response may have the potential to benefit blood related family members who take medication. Additionally, learning more about your genotype could help your practitioner come to quicker and easier medical decisions by highlighting the most ideal drug type for you, limiting unnecessary side effects.