What Your Genes Can Tell You About Pain
September is Pain Awareness Month, so I’m going to take a slight detour on answering questions for this post to focus on pain and the role that PGx testing can play when dealing with pain.
According to the Canadian Pain Taskforce, approximately 1 in 5 Canadians live with chronic pain. For many, finding the right treatment is a long, frustrating journey that interferes with their ability to function in everyday life.
Beyond chronic pain, I meet very few people who haven’t dealt with severe acute pain in their life. Whether it’s due to surgery, dental procedures, childbirth, or any number of other reasons, I would guess that most of you have had the experience of needing to manage pain.
Unfortunately, pain is very complex. Every person is unique and will have their own pain management needs based on lifestyle, gender, and a whole host of other reasons. But it's important to know that genetics have been found to play a role in how a person is likely to respond to a variety of pain medications.
Pain Medication & Genetic Interactions
A woman recently shared a story with me that illustrated the power of personalized medicine. After dental work and medical procedures, she was often prescribed codeine but she found that it never felt like it worked. She shared this feedback with doctors, and some accused her of using it as an excuse to ask for stronger medication - one even called her an addict.
Did you know? Up to 10% of people do not experience pain relief from codeine. Like Plavix (referred to in an earlier post), codeine is a prodrug, meaning it needs to be metabolized in the liver to create morphine (which provides the pain relief advertised), but as many as 10% of people lack this enzyme.
I’ve had a similar experience, though the opposite way: pain meds tend to work REALLY well for me. Whether it was for use after surgery, or just for aches and pains, even taking half a dose has often done the trick, and a full dose of strong meds made me feel really foggy.
While there are many, many factors that influence how much pain an individual feels, there are specific genes that have been found to play a part by influencing the effectiveness and toxicity of pain medications.
CYP2D6 influences opioids like codeine and tramadol. In addition to people who don't experience pain relief, for people with certain variations, they can be what’s called Ultrarapid Metabolizers, which can cause them to have overdose effects, even with a standard dose.
CYP2C9 influences some NSAIDS like ibuprofen, meloxicam and celecoxib. (In my case, I’m an Intermediate Metabolizer for CYP2C9, which means it’s recommended that I start with lower doses of some NSAIDS).
CYP2D6 and often CYP2C19 influence the effectiveness and likelihood of side effects for a class of drugs called tricyclic antidepressants (including amitriptyline, nortriptyline, desipramine, and imipramine) which are used for chronic pain.
How can you use this information?
Knowledge is power – and when we’re talking about pain which can be so debilitating, it’s especially powerful. PGx testing can be most helpful in identifying what medications are likely to have serious side effects.
So, consider getting a PGx test if...
...you’re having surgery or a medical procedure and you know you will be told to take pain medications. Knee and hip surgery patients reported less pain on average when PGx testing was used to inform treatment.
...you’re had side effects with anti-inflammatories including ibuprofen.
...you’re wary of your response to opioid painkillers such as codeine.
...you’re dealing with chronic pain. I won’t suggest that PGx is going to be the silver bullet in this scenario, for all of the reasons about the complexity of managing pain mentioned above, and the fact that many medications used for chronic pain don’t have useable PGx associations. But if you have the means, it can be helpful to validate past experiences, and to provide useful guidance for future medication use (and medications to avoid).
Because of the impact of pain on people’s lives, there are a good number of pain-specific PGx tests that are available. At Inagene, our Pain & Mental Health report is the most targeted one for this area.
Have any questions about PGx testing and pain medications? Feel free to let me know in the comments below or DM me and our research team would be happy to get back to you. Pain can be exhausting to manage – we're here to help.