The way our bodies respond to drugs and medicines can vary between individuals: While one person may feel the benefits of a particular drug, another may experience no benefit or negative side effects. It has been estimated that many key drugs are effective in only 30 to 60 per cent of patients due to these variations in individual responses.
Traditionally, this has meant a ‘trial-and-error’ approach to many medical treatments, in which patients and clinicians journey through the costs and side-effects of different drugs and doses in search of the most appropriate treatment.
The science of genetics and genomics is dramatically interrupting this process, opening up personalised treatment pathways.
Genomic testing to understand an individual’s likely drug responses is called ‘pharmacogenomic’ testing. In cases where only specific genes are examined (rather than the whole genome), the process is called ‘pharmacogenetic’ testing. These tests will usually be ordered by your GP or specialist and will most often require only a sample of your blood.
These kinds of tests allow scientists to identify the genetic variants and interactions that are responsible for your individual drug responses. This then enables your healthcare provider to select drugs that are more likely suited to your body.
Example of genomic testing at work: Warfarin
Warfarin, for example, is a common and effective treatment to prevent blood clots, but patients receiving the drug show a 40-fold difference in the doses required. The current ‘trial-and-error’ approach to discover the right dose for an individual means some suffer significant problems as their response to Warfarin is explored over time. Appropriate genomic testing can be used to see people receive the right dose of Warfarin sooner –cutting side-effects, saving money, and improving outcomes.
Avoiding adverse reactions
An estimated one in 15 hospital admissions in the UK are linked to adverse drug reactions. Thanks to insights now available through genetic and genomic testing, the ability to predict and prevent the occurrence of negative drug responses has significant potential to not only improve patient experiences, but also to reduce burden on accident and emergency units.
- NHS England: Improving outcomes through personalised medicine
- NHS Genomics Education Programme: What is pharmacogenomics?