methotrexate Side Effects

What the FAERS Data Reveals About methotrexate Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 410,053 voluntary reports linked to methotrexate and its brand equivalents (Trexall, Otrexup), spanning 1999 through 2025. Of those, 32,502 (7.9%) listed death as an outcome and 115,535 (28.2%) involved hospitalization. The most common indication reported alongside adverse events was Rheumatoid Arthritis.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 71% were female and 29% male; age distribution skews toward 45-64, with 105,081 reports in that bracket. The single most reported reaction is drug ineffective with 74,947 submissions, followed by rheumatoid arthritis and arthralgia.

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice — speak with a licensed clinician about any side-effect concerns.