[Correct use of methotrexate].

Insufficient knowledge about the correct dosage and potential implications of overdose have played an important role in recent accidents involving methotrexate (MTX). Therefore, it is important that the prescribing physician as well as the pharmacist and pharmacist's assistant have sufficient knowledge of the usual dosages, precautionary measures, side-effects, interactions and contraindications of MTX, to ensure a correct dosing regimen is prescribed. For nearly all indications, MTX is prescribed in a weekly dose of 5-30 mg and preferably in combination with 5 mg folic acid twice a week on a day that MTX is not used. The toxic dose of MTX lies very close to the effective MTX dose. It is therefore important to look out for signs of toxicity.