The patient should not be given any of the following: ajmaline, epinephrine, glucagon, guanethidine, histamine, high insulin doses, levodopa, lithium, nitroglycerin, or Raulwolfia alkaloids (increased VMA levels); or Clonidine, debrisoquin, disulfiram, guanethidine, imipramine, MAO inhibitors, morphine, Raulwolfia alkaloids, or radiographic agents (decreased VMA levels).
Specimens collected between 22-26 hours will be accepted as 24 hour specimens. Anything less than 22 hours or greater than 26 hours will be ordered as a "Random" specimen and should include a Period and Volume measurement.