Key investigations
Key investigations for suspected methotrexate poisoning should be performed on presentation to hospital in:
- adults following deliberate self-poisoning
- children who have accidentally ingested more than 5 mg/kg
- patients with suspected repeated supratherapeutic ingestions.
Key investigations include:
- serum electrolyte, urea and creatinine concentrations, and estimated glomerular filtration rate (eGFR)
- full blood count
- liver biochemistry.
Serum methotrexate concentration is not useful in the management of acute or repeated supratherapeutic methotrexate ingestions.