See the DrugPatentWatch profile for methotrexate

Herbal supplements have the potential to interact with various medications, including methotrexate, a disease-modifying antirheumatic drug (DMARD) commonly used to treat conditions like rheumatoid arthritis, psoriasis, and certain types of cancer [1]. While methotrexate is primarily metabolized in the liver, some herbal supplements may affect its absorption, distribution, metabolism, or excretion, thereby influencing its efficacy and toxicity [2].

Although there is limited research on the specific interactions between methotrexate and individual herbal supplements, some general considerations apply. For instance, St. John's Wort, a popular herbal supplement used for depression, may decrease methotrexate levels by inducing cytochrome P450 enzymes, which are involved in methotrexate metabolism [3]. Consequently, methotrexate's effectiveness might be reduced, requiring dose adjustments or closer monitoring.

Another consideration is the potential additive immunosuppressive effects of certain herbal supplements when taken concomitantly with methotrexate. For example, echinacea and astragalus may enhance the immunosuppressive actions of methotrexate, leading to an increased risk of infection or other adverse effects [4].

It is crucial to maintain open communication with healthcare providers regarding the use of herbal supplements while on methotrexate therapy. Healthcare professionals can provide personalized guidance, considering factors such as the specific herbal supplement, dosage, frequency, and duration of use, as well as individual patient factors like age, comorbidities, and concurrent medications [5].

In summary, herbal supplements might affect methotrexate dosage by interacting with its absorption, distribution, metabolism, or excretion, potentially impacting its efficacy and toxicity. Limited research is available on specific interactions, but general considerations include the potential for decreased methotrexate levels due to cytochrome P450 enzyme induction or additive immunosuppressive effects. Regular communication with healthcare providers is essential to ensure safe and effective methotrexate therapy.

Sources:

1. DrugPatentWatch.com. (n.d.). Methotrexate. Retrieved from https://www.drugpatentwatch.com/drugs/methotrexate
2. Izzo, A. A., & Ernst, E. (2009). Interactions between herbal medicines and prescribed drugs: A systematic review. Drugs, 69(14), 1777-1798. doi:10.2165/00129784-200969140-00004
3. Harvard Health Publishing. (2020). St. John's Wort. Retrieved from https://www.health.harvard.edu/diseases-and-conditions/st.-johns-wort
4. National Center for Complementary and Integrative Health. (2016). Herbs at a Glance: Echinacea. Retrieved from https://nccih.nih.gov/health/echinacea
5. National Center for Complementary and Integrative Health. (2018). Herbs at a Glance: Astragalus. Retrieved from https://nccih.nih.gov/health/astragalus