[Wrong administration of methotrexate can lead to fatal haematological complications in elderly patients].

We present four cases of life-threatening methotrexate intoxications of patients with rheumatological disease. In two of the cases, the direct cause of intoxication was accidentally daily administration of the drug instead of weekly. The patients presented with uncharacteristic symptoms, including nausea, mucositis and fever. All of them had pancytopenia, and despite therapy with broad spectrum antibiotics three patients died in a state of septic shock. These cases demonstrate the importance of adequate communication between health-care professionals, who are involved in the administration of methotrexate and in particular it emphazises that methotrexate should be administrated as weekly doses.