Observation and patient disposition after methotrexate poisoning

Admit the following patients for treatment of methotrexate poisoning:

• adults with pre-existing kidney impairment
• patients with impaired kidney function or evidence of methotrexate toxicity—patients with bone marrow suppression require management in a specialist haematology/oncology unit with barrier nursing.

The following patients can be discharged with oral calcium folinate treatment, provided they do not meet the criteria for admission, and their full blood count and liver biochemistry are normal:

• children with accidental ingestions of more than 5 mg/kg of methotrexate
• adults with acute ingestions of more than 1000 mg of methotrexate.

The following patients can be discharged without treatment:

• children with accidental ingestions of less than 5 mg/kg of methotrexate
• adults with acute ingestions of less than 1000 mg of methotrexate and normal kidney function.

All patients should be advised to seek medical attention if they develop symptoms of toxicity, such as fever, sore throat, mouth ulcers, bruising, nausea, vomiting or diarrhoea, or if they are feeling generally unwell within 5 to 10 days of methotrexate ingestion.