laboratory diagnostic - drugs - Isoniazid, INH, serum. The sample must be frozen within 4 hours after collection and must be sent in the frozen samples container(!), Collect the sample 3hrs after administration. Allways specify patient's weight and dose administered. 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), HPLC/UVD, ssso, todylaboratories®, bmn, code L16LD1429