laboratory diagnostic - drugs - Methadone, serum 2ml. Always sample at the same time before another administration. All requests must ALWAYS contain: sampling date and time; the date and time of the last dose; the reasons for the prescription (efficiency and/or toxicity test); the treatment start date and/or the date of any change of dosage; the subject's age, height and weight, when possible; the dosage data (quantity administered, frequency, administration route), The serum must be frozen within 1 hour after collection and must be sent in the frozen samples container(!), GC-MS, ssso, todylaboratories®, bmn, code L16LD1446