Is your medication working?

New developments in genetic testing now provide more effective and acute relief for patients – and expose shortcomings in a ‘one-dose-fits-all’ treatment approach. Increasing evidence suggests personalised treatment informed by genetics yields better outcomes for the patient. This means by taking a simple genetic test, you can avoid medicines to which your body might be unresponsive, or which produce harmful side effects.

How does it work?
Personalised medicine and tailored treatment is based on pharmacogenomics. Pharmacogenomics is the study of how our genes affect the body’s response to medicines. Once perceived as invasive and expensive, pharmacogenomic testing is now affordable and available in South Africa. Some tests, like Medcheck, are as simple as a cheek swab done in the comfort of your home.

Analysis of your gene sample will highlight genetic ‘variants’ that affect how you absorb and process drugs. This information is then used by a healthcare practitioner – like your doctor, psychiatrist or cardiologist – to guide the medicines they prescribe you.

The facts
The benefits of pharmacogenomics have come to light recently as healthcare practitioners and patients discover that medicines designed to treat the majority of the population can be decidedly less affective for certain people. Although the DNA of any two individuals is 99.9% identical, small genetic variations in the 0.1% can dramatically impact drug response.

Molecular biologist and founder of DNAlysis Biotechnology, Dr Danny Meyersfeld, encourages patients to interrogate whether their medication is, in fact, giving them the benefits it should.

“If you’re requiring doses outside the recommended range, aren’t responding to certain medications or experiencing severe side effects, it’s vital to check whether your genes are affecting the metabolism of drugs in your body,” says Meyersfeld. “Not only will this explain how your body is processing – or not processing – medication, it ensures the safety of future possible treatments.”

Knowledge gap
Meyersfeld explains that, without the knowledge of their DNA, patients might unknowingly take medication for years – or in direct response to an acute medical need, like after surgery – with severely diminished effectiveness. Patients seeking pain relief from codeine (a commonly prescribed painkiller), for example, might not know they possess a gene that makes them less susceptible to its effects.

Many common antidepressant therapies are metabolised differently according to the patient’s DNA, and might not provide the benefits intended. Warfarin, a commonly prescribed blood thinner, is affected by genetic variations in the patient and, for some patients, won’t provide potentially life-saving treatment.

Targeted treatment
Personalised medicine can also reduce the risk of harmful side effects. “It’s estimated that around 5% of hospital admissions are caused by adverse drug reactions (unintended side effects), and in low- and middle-income countries, that statistic is likely as high as 8%,” says Meyersfeld. “Through genetic testing, medicines can be flagged as potentially dangerous for the patient and avoided in their treatment plan. Not only is this essential for adults currently on medication, it’s something parents should do for their children to give them the gift of safety for future treatments. Your DNA doesn’t change, so doing a genetic test once reaps lifelong benefits.”

The rise of pharmacogenomic testing and personalised medicine speaks to the larger need for patients to be empowered about their health. By knowing what works for them and what doesn’t, patients can save time, money and ensure safer treatment by using the right medication, at the right dose – and seeing results.