See the DrugPatentWatch profile for methotrexate

Age can impact the optimal dosage of Methotrexate, a medication commonly used to treat various conditions such as rheumatoid arthritis, psoriasis, and certain types of cancer [1].

For adults, the typical dosage range for methotrexate is 7.5 to 30 milligrams (mg) once a week for rheumatoid arthritis and 10 to 30 mg per week for psoriasis [2]. However, for older adults, particularly those with impaired kidney function, the dosage may need to be reduced due to the body's decreased ability to eliminate the drug [3]. This is because methotrexate is primarily excreted by the kidneys, and impaired kidney function can lead to increased levels of the drug in the body, increasing the risk of toxicity [4].

Additionally, older adults may be more susceptible to the side effects of methotrexate, such as bone marrow suppression, liver toxicity, and gastrointestinal disturbances [5]. Therefore, it is essential to closely monitor older adults taking methotrexate and adjust the dosage as necessary to minimize the risk of adverse effects [6].

In summary, age can affect the optimal dosage of methotrexate, particularly in older adults with impaired kidney function. Healthcare providers should closely monitor older adults taking methotrexate and adjust the dosage as necessary to minimize the risk of adverse effects.

Sources:

1. Mayo Clinic. (2021). Methotrexate (Oral Route). Retrieved from <https://www.mayoclinic.org/drugs-supplements/methotrexate-oral-route/description/drg-20062759>.
2. American College of Rheumatology. (2019). 2019 American College of Rheumatology Guideline for the Management of Rheumatoid Arthritis. Retrieved from <https://acrabstracts.org/abstract/2019-american-college-of-rheumatology-guideline-for-the-management-of-rheumatoid-arthritis/>.
3. UpToDate. (2021). Methotrexate: Indications, dosage, and adverse effects. Retrieved from <https://www.uptodate.com/contents/methotrexate-indications-dosage-and-adverse-effects?search=methotrexate%20dosage&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1>.
4. National Library of Medicine. (2021). Methotrexate. Retrieved from <https://medlineplus.gov/druginfo/meds/a682132.html>.
5. American Academy of Dermatology. (2021). Methotrexate. Retrieved from <https://www.aad.org/public/diseases/psoriasis/treatment/biologics/methotrexate>.
6. DrugPatentWatch. (2021). Methotrexate. Retrieved from <https://www.drugpatentwatch.com/drugs/methotrexate>.