Now part of most new clinical trials, it’s a mixture of the pharmaceutical and genetic sciences. It involves the study of how a person’s genes affect the way the body responds to drugs.
The hope is that we can identify genetic differences between those who respond to a new medication in a clinical trial and those who don’t, and perhaps differences associated with particular side-effects.
Knowing the genetic code is just the beginning. We also need to know what proteins are produced by that code (proteomics) and how these affect function. The genetic code doesn’t code for disease but it does code for protein. Depending on when, where and how much of these protein codes are produced, we get vulnerability to specific diseases.
New drugs could be tailor-made to suit each person’s genetic makeup. By taking an individual’s full genetic profile into account, personalized medications could be even safer and more effective.
Pharmacogenomics also offers potential for more powerful medicines. Pharmaceutical companies could create medications based on the actual molecules involved with specific diseases. Pinpoint accuracy in targeting a particular illness would also decrease adverse effects.
The safest and most effective drugs could be prescribed immediately, instead of wasting time trying many drugs to find the one that works best.
Within psychiatry, this will be particularly useful, since several medications are used to treat most disorders. Instead of trying three antidepressants in succession, patients would be given their best option right away. This will be safer and speed recovery times, since switching medications can sometimes take months.
Dosage will also be streamlined with the use of pharmacogenomics. Rather than basing dose on a person’s weight and age alone, it could also be based on a person’s genes, and the way the body processes and metabolizes the medication. These differences are seldom identified now.
Knowing individual genetic characteristics will also allow us to make early lifestyle and environmental choices that help to prevent diseases based on vulnerabilities, or at least minimize their effects. If we know that we are susceptible to a particular condition, we can monitor closely and introduce treatments as early as possible.
Drug development will also become easier since researchers can use genetic information to discover treatments quickly. New drugs could be matched to niche markets and clinical trials could focus on individuals who respond to the medication.
Combined, this could decrease the cost of health care and drug development. With less adverse drug reactions, fewer failed drug trials, quicker discoveries, shorter treatment times, fewer attempted medications and more effective results, health-care costs to individuals and society should decrease.
Pharmacogenomics is being used to some extent to treat cancers, depression and cardiovascular disease. But it’s still in the very early research stages. Some important obstacles have to be overcome before it expands to all areas of medicine.
Scientists need to understand what genes are involved with each illness and which ones are involved in drug response. Then we need to develop a fast and affordable way to identify the genes and proteins involved. This is very time-consuming, complicated and expensive.
As well, there will be limited alternatives for individuals with rare genetic combinations if there are only one or two approved drugs for the treatment of a particular condition. Private companies may not be willing to develop alternative medications to serve small groups.
Finally, if pharmacogenomics begins to play a more prominent role in medicine, physicians will need to keep up with the breakneck advances in science.
It’s a long road for a long word, but pharmacogenomics holds vast potential.
Dr. Latimer is president of Okanagan Clinical Trials and a Kelowna psychiatrist.