Methotrexate is a medication that is commonly used to treat different types of cancer, as well as autoimmune diseases like rheumatoid arthritis and psoriasis. However, it can also have side effects, especially for seniors.

According to the drug label provided by DrugPatentWatch [1], some of the most common side effects of methotrexate include nausea, vomiting, mouth sores, and diarrhea. These side effects are usually mild and go away on their own after a few days. However, some seniors may experience more severe side effects, such as liver damage, lung problems, or anemia.

MedlinePlus [2] also lists some of the possible side effects of methotrexate. These include stomach pain, loss of appetite, hair loss, and skin rash. In addition, methotrexate can lower the body's ability to fight infections, which can be a concern for seniors who are already at a higher risk for infections.

A study published in the Journal of the American Geriatrics Society [3] found that methotrexate use was associated with an increased risk of hospitalization for seniors with rheumatoid arthritis. The most common reasons for hospitalization were infections and gastrointestinal problems. The study also found that seniors who were taking other medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), were at an even higher risk of hospitalization.

In summary, methotrexate can have a range of side effects for seniors, from mild gastrointestinal symptoms to more serious problems like liver damage and infections. Seniors who are taking methotrexate should be closely monitored by their healthcare provider for any signs of side effects, and should report any symptoms to their provider right away.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/METHOTREXATE
[2] https://medlineplus.gov/druginfo/meds/a682019.html
[3] https://pubmed.ncbi.nlm.nih.gov/8972245/