Part 2 of the methotrexate mini series discusses a few over-the-counter (OTC) drug interactions I have on my radar! When I start a new medication I want to know of potential drug interactions. That was the case when I started on methotrexate (MTX). Your pharmacist is a valuable resource to review your prescription profile for any prescription drug interactions. It is the OTC medication interactions that could easily be missed. I want to highlight a few.
- The first is high-dose aspirin. Aspirin is used to treat pain, is inexpensive and readily available. Therefore, I could see where an arthritic patient could pick some up at the local grocery store to ease the pain we often experience. At a dose of 1,300 mg per day or higher, serum concentrations of MTX can increase perhaps to levels of MTX toxicity. Low-dose aspirin, one or two tablets per day, is usually not a problem.
- Other non-steroidal anti-inflammatory drugs (NSAID), aspirin is the original, such as OTC drugs branded Motrin, Advil or Aleve, can irritate the GI tract as MTX can. Therefore, tell your doctor if you are taking any NSAID especially if you experience bloody or black tarry stools. This would indicate bleeding in the GI tract perhaps caused by irritation.
- An interaction getting renewed interest these days is between MTX and a type of medication available OTC called proton pump inhibitors (PPI) marketed as brand names Prilosec, Nexium, and Prevacid. PPIs are used to treat gastric reflux. Prescription medications used for RA often have GI side effects so self medication with a PPI could be very natural. This interaction is not seen in all patients and more often occurs with the high MTX doses used in oncology, but in some individuals PPIs elevate MTX levels by inhibiting its excretion causing MTX toxicity. Tell your doctor if you take a PPI so they have a more accurate account of your medication regime. If your lab values used to monitor the MTX should be out of whack, the PPI could be the reason.
- Alcohol is also on my radar. Use of alcohol while taking MTX may increase risk for liver problems. Personally, I limit my alcohol consumption to a holiday or anniversary toast. I then can celebrate, but I don’t put my health at risk.
I get all my prescriptions filled at the same pharmacy. A complete record of what I’m taking is therefore available to review for potential drug interactions. Aspirin, NSAIDS, PPIs and alcohol were just a few OTC medications I may take, therefore I put them on my radar while I’m taking MTX. Perhaps you use them too! If so, be aware of these potential drug interactions and be sure to let your doctor know if you use them. Before I sign off I’d like to mention herbal and natural supplements. There are many unknowns concerning interactions with herbal supplements. Until I’m comfortable with my sources addressing the issue, I won’t comment. As always, I would love to hear of your experiences. Stay tuned for Part 3! We will talk about MTX monitoring! *Cathy*