24 hr urine in 15 mL 50% HCl
Minimum aliquot volume : 30 mL urine
Total 24 hr urine volume must be clearly indicated
High Performance Liquid Chromatography
≥ 20 yrs Metanephrine : 400 - 1500 nmol/day ≥ 20 yrs Normetanephrine : 600 - 1900 nmol/day For subjects 19 yrs and below, results are expressed as per mmol creatinine (see individual tests)
Mean = 7 days, Range: 3 – 11 days
Monday - Friday
Patient Preparation:(1) Patient should abstain from the following at least 2 days prior to and during urine specimen collection:
(a) where medically possible, drugs such as alpha-methyldopa (AldometTM), Buspirone, Codeine, Isoproterenol Metabolite, Mandelamine, Metoclopramide and acetaminophen which may potentially interfere with the testing
(b) where medically possible, drugs such as tricyclic antidepressants (e.g Amitriptyline), α-blockers (Nonselective) (e.g Phenoxybenzamine), α-blockers (α1 - selective) (e.g Doxazosin), β-blockers (e.g Atenolol), Calcium Channel Antagonists (e.g Nifedipine), Monoamine Oxidase Inhibitor (e.g Phenelzine) and Sympathomimetics (e.g Ephedrine) which may induce increase or decrease in the metanephrine production.
(2) If the patient cannot be completely removed from a drug regime, test result should be interpreted with appropriate clinical judgement based on expected physiology response to these drugs.