Medication errors involving the use of the powerful cytotoxic agent methotrexate have resulted in serious harm to patients, including death, according to the US Pharmacopeia (USP) Medication Errors Reporting Program.
Since 1991, the program has received more than a dozen reports of errors in dosing, directions for use, and order interpretation involving methotrexate. In 1 case, a 20-year-old patient with renal failure died within 2 weeks after taking methotrexate that a pharmacist dispensed instead of metolazone. In another instance, a patient being treated for psoriasis was hospitalized and eventually died after taking methotrexate every 12 hours for 6 consecutive days instead of every 12 hours for 3 doses each week as instructed.
Stephenson J. Methotrexate Errors. JAMA. 1998;279(11):818. doi:10.1001/jama.279.11.818-JHA80001-4-1