Methotrexate is a medication used to treat various conditions such as cancer, autoimmune diseases, and ectopic pregnancies. While it is generally well-tolerated, there are potential side effects that can occur, particularly in elderly patients.

According to DrugPatentWatch [1], some of the most common side effects of methotrexate include nausea, vomiting, fatigue, and decreased appetite. In elderly patients, these side effects may be more severe due to age-related changes in the body's ability to metabolize and eliminate the drug. Additionally, methotrexate can cause bone marrow suppression, which can lead to an increased risk of infection, bleeding, and anemia.

A study published in the journal Drugs & Aging [2] found that elderly patients taking methotrexate for rheumatoid arthritis had a higher risk of adverse events compared to younger patients. The study also noted that the risk of side effects increased with higher doses of methotrexate.

Another study published in the British Journal of Clinical Pharmacology [3] found that elderly patients taking methotrexate for psoriasis had a higher risk of liver toxicity compared to younger patients. The study suggested that close monitoring of liver function is important in elderly patients taking methotrexate.

In conclusion, while methotrexate is generally well-tolerated, there are potential side effects that can occur in elderly patients. These side effects may be more severe due to age-related changes in the body's ability to metabolize and eliminate the drug. Close monitoring of side effects and liver function is important in elderly patients taking methotrexate.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/METHOTREXATE
[2] https://pubmed.ncbi.nlm.nih.gov/8972245/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1741826/