Can Rheumatoid Arthritis Medications Cause Serious Side Effects?

How DNA Testing Can Help You Choose the Right Drug for RA

What is the best treatment for Rheumatoid Arthritis (RA)? Let me tell you a story. Twenty-five years ago, my mum was diagnosed with rheumatoid arthritis (RA). I was away from home at this time, but my dad tells me that the treatment endgame was to get her on a biologic medicine: Infliximab.

However, infliximab is an expensive medication for the NHS, so the path to treatment is via other drugs first to see if they work. In my mother’s case, these were Methotrexate and Prednisolone.

Do RA Medications Have Lots of Side Effects?

Methotrexate is a drug whose efficacy is affected by our genes. The MTHFR gene can influence folate metabolism and impact Methotrexate (MTX) therapeutic outcome and potential toxicity.

Based on my genetic phenotype, I can reveal that I have the G/G variant of MTHFR, meaning that if I needed Methotrexate, I would have a decreased risk of toxicity.

But what variant did my mother have? And what was the cost of methotrexate to her system?

Sadly, she has passed, so this is an unanswerable question. The kicker is, she died of leukaemia—possibly a side effect of Methotrexate, which has a deleterious effect on bone marrow over time.

Is There a Better Way to Treat RA Today?

Medications aren’t one-size-fits-all. Each person metabolises drugs differently based on their genes. Some people break down medications too quickly, meaning a standard dose might not reach therapeutic levels. Others process medications slowly, increasing the risk of side effects and toxicity as a result of accumulation of the drugs in their plasma beyond the safety level.

Without knowing this in advance, doctors are left to guess, adjusting the treatment plan based on averages and their personal experience.

Pharmacogenomics and Better Patient Outcomes

The key to understanding our genes and drug-gene interactions lies in pharmacogenomic (PGx) testing (sometimes called pharmacogenetics). A PGx test is a simple, painless swab of the inside of your cheek.

Within 2 weeks, the AttoDiagnostics PGx test provides insights into how your body processes over 115 medications across various conditions, from pain management to mental health and heart disease.

With this knowledge, your doctor can:

• Avoid ineffective medications – You won’t waste time and money on drugs that don’t work for you.
• Reduce side effects – By knowing how you metabolise a drug, they can choose the right dose or alternative to minimise toxicity.
• Speed up treatment success – Finding the right medication faster means you feel better, sooner.

Methotrexate vs. Sulfasalazine: Is There an Alternative?

Has Methotrexate ever given you side effects? Let’s visit another case close to home, that of Kelly L, wife of Avi L, a former boss of mine. One day, we were talking outside of work, and he mentioned that Kelly suffered from RA. I shared my story about my mother, Methotrexate, and leukaemia.

As you can imagine, when PGx testing came on the scene, Avi was quick to recommend that Kelly take the test.

To her benefit, the test revealed that Methotrexate was not suitable for Kelly. Armed with this information, she was able to approach her doctor and transition to Sulfasalazine, which has proven to be a more effective medication for her, with fewer side effects—both long and short-term.

What Happens if You Need to Take Multiple Medications?

In the medical world, a person taking multiple medications is called a polypharmacy patient. Taking more than one drug adds complexity to an already complex situation.

• Gene-Drug interactions – How your DNA influences your response to a drug.
• Drug-Drug interactions – How drugs interfere with each other.
• Food-Drug interactions – Yes, even what you eat can impact medication!

Did you know grapefruit juice affects medications?

For example, quetiapine and some benzodiazepines (such as diazepam) rely on CYP3A4, which can be inhibited by grapefruit juice, leading to unexpectedly high drug concentrations in the bloodstream.

Polypharmacy Considerations: What About Methotrexate?

To put you in your doctor’s shoes, a person taking multiple medications needs to consider whether one drug will affect the metabolism of another. Let’s look at Methotrexate in the table below. You can see that many common medications—from ibuprofen to alcohol—affect MTX, with knock-on effects on other organs.

Major Drug-Drug Interactions for Methotrexate

 

What Should I Do if I Have Been Prescribed Methotrexate?

This is serious subject matter with serious life implications. As a consumer, you might be offered a PGx test through the NHS or via your private doctor. Alternatively, if you have been prescribed Methotrexate but aren’t experiencing relief, you can order your own test and take the evidence to your specialist.

Rest assured, in our reports, all guidance is backed by robust studies and FDA guidelines. Snake oil this is not.

If you’re lucky enough to be seeing a forward-thinking private doctor, you might be offered one of our tests. The good news is that AttoDiagnostics provides both gene-drug interactions and drug-drug interactions, so that you can optimise your treatment, experience maximum relief, and minimise side effects.

Explore the Comprehensive PGx Test