An alert from the Institute for Safe Medication Practices warns of cases in which oral methotrexate was accidentally prescribed for daily instead of weekly administration. The drug is given on a daily basis for cancer treatment but is prescribed in low weekly doses for asthma, as well as rheumatoid arthritis, psoriasis, inflammatory bowel disease, and other disorders.
In order to prevent overdose, the organization suggests building alerts into electronic prescribing systems and pharmacy computers to warn clinicians whenever oral methotrexate is entered so that indication and dosing frequency can be assessed. The system also should alert pharmacists to counsel patients on proper dosing. If the purpose of the medication is not made apparent, pharmacists should speak directly with the prescriber to determine the reason for use and verify to the proper dosing schedule.