The European Medicines Agency is reviewing methotrexate, a drug used to treat certain cancers and inflammatory diseases, after finding that dosing errors leading to serious adverse events are still occurring.

The drug is taken once weekly for treating inflammatory diseases like psoriasis and arthritis, but its use in cancer treatment calls for more frequent and higher doses. Mistakes have led to patients taking doses daily instead of once a week, sometimes with fatal consequences.

The EMA’s Pharmacovigilance Risk Assessment Committee will develop recommendations on ways to minimize the errors.