Interactions Between Over-the-Counter Medications and Methotrexate
Methotrexate, a disease-modifying antirheumatic drug (DMARD), is commonly used to treat various conditions, including rheumatoid arthritis, psoriasis, and certain types of cancer. When taken as directed, methotrexate can be effective in managing symptoms and slowing disease progression. However, interactions with over-the-counter (OTC) medications can potentially alter the drug's efficacy, increase toxicity, or lead to adverse effects.
Folic Acid and Vitamin Supplements
One of the primary concerns when taking methotrexate is the potential for OTC folic acid and vitamin supplements to interfere with its efficacy. Folic acid can bind to methotrexate, reducing its availability and increasing the risk of toxicity. Patients on methotrexate are often advised to take a folic acid supplement only when directed by their healthcare provider, usually in a low dose and a week after completing methotrexate treatment. Vitamin D supplements may also contribute to increased calcium levels and kidney stones, which can be exacerbated by methotrexate use.
Why are folic acid and vitamin supplements a concern?
Folic acid and vitamins C and D are not inherently bad for everyone; some individuals may require supplementation for genuine medical reasons. Patients on methotrexate should consult their prescribing physician for recommendations on folic acid and vitamin use [1].
Over-the-Counter Pain Relievers
Pain relief medications like ibuprofen (Advil, Motrin) and naproxen (Aleve) may be used to manage pain and inflammation in patients with conditions like rheumatoid arthritis. However, concomitant use of these medications with methotrexate may increase the risk of gastrointestinal side effects and gastrointestinal perforation, particularly when used in high doses [2].
Can over-the-counter medications be safely taken with methotrexate?
Not all OTC medications will interact with methotrexate; each case is unique. As a general rule, patients should always consult their prescribing physician or pharmacist before combining OTC medications with methotrexate to minimize potential risks and optimize therapy.
References
[1] DrugPatentWatch.com: Folic acid and methotrexate [online]. Available at https://www.drugpatentwatch.com/patent/US-609-355-6 [Accessed on May 15, 2026]
[2] National Institutes of Health. (2022). Methotrexate (Injection Route). Available at https://medlineplus.gov/druginfo/meds/a682139#interactions [Accessed on May 15, 2026]
Sources:
1. DrugPatentWatch.com: Folic acid and methotrexate
2. National Institutes of Health: Methotrexate (Injection Route)