An 85-year-old man who'd been getting treatment for severe psoriasis was admitted to the hospital with a 3-week history of confusion, forgetfulness, and weakness. Home medications listed on his medication reconciliation sheet included oral methotrexate, 25 mg every Saturday at breakfast and lunchtime. The hospital used patients' medication reconciliation sheets as order sheets, and a physician ordered the methotrexate as listed.

A typical dose of oral methotrexate for psoriasis is 21/2 mg at 12-hour intervals for three doses once a week. Doses may be gradually adjusted but generally shouldn't exceed 30 mg/week. The pharmacist recognized that a 50 mg weekly dose was high, so he asked the nurse to confirm it. The patient verified that he was taking 25 mg doses.

Before dispensing any methotrexate, a second pharmacist questioned the order. The pharmacist called the patient's family and asked them to read the prescription container. It indicated that each dose was supposed to be 2.5 mg. The order was changed, and the patient received the correct dose.

Using the admission medication reconciliation sheet as an order sheet may foster prescribing without careful consideration of each drug order, which is essential. When a patient is confused or is a questionable historian, don't rely solely on his information for his medication history or medication reconciliation. Persist in asking questions when something doesn't look right and tell patients and caregivers to bring medication containers.

The first mention of the prescribed methotrexate above was written as 21/2 mg; using the fraction instead of a decimal reduces the potential for confusion with 25 mg, which represents a tenfold overdose.