Quantitation of urine normetanephrine (NMN) and metanephrine (MN), collectively referred to as “metanephrines,” together with plasma metanephirne levels is useful as the initial screen to aid in the diagnosis and follow-up of catecholamine-producing tumors, pheochromocytoma and paraganglioma. 24-hr urine is highly recommended.
Patients should be off Buspirone ("Buspar") for 72 hours before collection as the drug may cause false elevations of metanephrine.
Patients should be off of Sinemet (Levodopa or Carbidopa), L-Dopa, Aldomet (Methyldopa) and methanamine mandelate (Hiprex, Mandelamine, Urex) for 1 week (minimum of 48 hours) prior to collection.
Monday, Wednesday, Friday
Normetanephrine: 69 – 750 ug/g creatinine
Metanephrine: 27 – 270 ug/g creatinine