Genetic differences mean that a drug can be safe and effective for one person but harmful for another. One person may experience side-effects while another does not, even though they may have been prescribed the same dose. This presents a problem to doctors who have to rely on a trial and error approach to prescribing.
Trial & error approach to prescribing medicine
The difficulty with such an approach is that, until doctors find the right drug or the right dose, a patient’s symptoms can worsen or they may suffer unpleasant side-effects. If the patient is suffering from a rapidly developing illness, it may worsen making it harder to treat or leading to complications.
In the case of Crohn’s disease, for example, which is an inflammatory bowel disease, finding the right drugs is important to prevent bowel narrowing or perforation of the intestine. In people with the most aggressive form of the disease, complications can occur within a few months and may require extensive surgery.
Not only is it potentially damaging to patients to have to keep trying different drugs until the right one is identified but it is also costly.
Up to 50% of people don’t respond to the first drug
Studies show that 40-50% of people will not respond to the first drug that doctors try for conditions such as asthma, diabetes and arthritis.
Up to 50% of patients with depression are reported to be unresponsive to the first drug that is prescribed.
People with bipolar disorder experience relapse rates as high as 70% and 75% of patients with schizophrenia discontinue treatment within 18 months due to intolerable side-effects.
These statistics speak for themselves in demonstrating that this trial and error approach to prescribing medicine does not produce good results for the patient, as it assumes we are all the same, where as in reality each person is uniquely different.
Pharmacogenomics: What is it?
Pharmacogenomics is the study of how medicines interact with inherited genes. Whereas genetic testing searches for specific genes that may increase an individual’s chances of developing serious illnesses (such as the BRCA1 and BRCA2 genes which are linked to an increased risk of ovarian and breast cancer), pharmacogenomics looks for variations in the genes which affect how the individual will respond to particular drugs.
This information helps doctors to predict which drugs are likely to be the safest and most effective and what sort of dose should be prescribed.
In clinical studies, 91% of treatment-resistant patients showed clinically measurable improvements following genetic testing.
Pharmacogenomics is considered to be a highly effective way of tailoring treatments to the individual to achieve better outcomes in the shortest timeframe.
Why people respond differently to drugs
To understand why genetic differences make a difference to our individual responses to drugs, you need to understand how many of these drugs work.
Often they require enzymes in the body to activate the drug so that it can begin to work. Each of us has slightly different enzymes which affect how quickly the drug can be activated. If people have enzymes that break down drugs slowly a standard dose treatment may not be effective and they may require a higher dose.
Drugs also need to be deactivated to limit their exposure to healthy tissues. In people with slower-acting enzymes, the process of deactivation takes longer which means the drug remains in their system for more time increasing the chances of side-effects.
Other factors besides genetics influence a drug’s effectiveness including age, gender, lifestyle and other conditions.
Pharmacogenomics: a simple accurate test
Myogenes’s offer simple saliva -based genetic tests that analyse over 200 variants within 50 well-established pharmacogenomics genes.
They can be used to provide accurate information on medication response for a wide array of conditions including depression, anxiety, bipolar disease, autism, OCD, substance abuse, ADHD, PTSD and schizophrenia.