Food Politics

The Wonderful World of Pharmacogenomics


I don’t know about you but when I see an ad for a prescription drug on television I often wonder why anyone in the world would take it.    Although the ad usually portrays the patient as happy and much improved after taking this medicine, all the side effects are then announced.  Many of those side effects sound worse than what they were prescribed for in the first place!  Many people also know someone who has actually been harmed by a medicine they were on.  My own personal experience involves my father-in-law, whose kidneys were damaged from a blood pressure medicine he was prescribed.  All of this becomes even more of a concern when you learn that only 50% of people are actually helped by their medications!

Doctors prescribe medications because they are necessary to cure or manage a medical condition.  Medications affect specific biochemical pathways in the body, which is why they are effective.  Patients, rightly, trust their doctor will prescribe a medicine that will be the most safe and effective for them, while also letting them know what side effects are possible. Until recently, drugs  were prescribed with the idea that each drug works the same for everyone.  But genomic research has opened the door to a more personalized approach to prescribing medications.  99% of people have at least one gene that impacts their ability to metabolize, absorb, and remove the harmful end products their medication generates.  The Centers for Disease Control and Prevention (CDC) reported in 2016 that almost 7 million people visited an emergency room due to a bad medication reaction.  Until now doctors had no way of knowing whether a drug would be effective or harmful for their patient.  But now they do.

Enter the world of pharmacogenomics.  Pharmacogenomics studies how genes affect the way a person responds to a medication. If you remember from the previous blog post, Nutrition Can and Does Affect The Genes You Are Born With, gene SNPs affect how a person reacts to their environment, either positively or negatively.  Gene SNPs also determine how well a person metabolizes and absorbs medicine and clears their body of the drug.  The most important genes controlling this process are the Cytochrome P450 (CYP450) enzymes made from the CYP genes.

Doctors are just beginning to use pharmacogenomics information to prescribe drugs.  However, this field is in its infancy and only certain gene SNPS for specific diseases are currently tested.  For example, breast cancer patients are routinely tested before prescribing the drug Herceptin, which only works for tumors that have a specific genetic profile that results in the overproduction of the protein HER2.  The U.S. Food and Drug Administration (FDA) also recommends genetic testing before the chemotherapy drug Purinethol (mercaptopurine) is prescribed because some people have a genetic variant that reduces their ability to process the drug resulting in serious side effects.  Knowing your gene SNPs insures that the most safe drug for you as an individual is prescribed at the correct dosage that will be most effective.

You can order your own pharmacogenomics report currently.  But beware – while there are some very reputable companies out there, many of these companies do not always provide accurate results.  The company, how they process your genes, privacy policies, and independent analysis of the accuracy of their services are all important to investigate before ordering a pharmacogenomics report.  Also keep in mind that most insurances do not cover pharmacogenomics reports and testing can be quite expensive. But pharmacogenomics is rapidly advancing and is soon expected to lead to better ways of using drugs to manage heart disease, cancer, asthma, depression and many other common diseases while also making the drugs we take more effective and safe.