24 hour urine refrigerated during collection. Record total
volume. Transfer 10 mL from a well-mixed 24 hr collection
to a plastic aliquot tube. Freeze. When multiple tests are
ordered, submit separate sample for this test.
If possible, patient should abstain from medications for
72 hours prior to collection. Medications that may
physiologically interfere with catecholamines and
metabolites include amphetamines and amphetamine-like
compounds, appetite suppressants, bromocriptine, buspirone,
caffeine, carbidopa-levodopa (Sinemet), clonidine,
dexamethasone, diuretics (in doses sufficient to deplete
sodium), ethanol, isoproterenol, methyldopa (Aldomet),
MAO inhibitors, nicotine, nose drops, propafenone (Rythmol),
reserpine, theophylline, tricyclic antidepressants, and
vasodilators. The effects of some drugs on catecholamine
results may not be predictable.