Ordering Guidance

This assay is of greatest value when the specimen is collected during a hypertensive episode.

Do not perform the test on patients withdrawing from legal or illegal drugs known to cause rebound catecholamine release during withdrawal (see Cautions).

This test is not a first-line test for pheochromocytoma. The recommended first-line laboratory tests for pheochromocytoma are PMET / Metanephrines, Fractionated, Free, Plasma; and METAF / Metanephrines, Fractionated, 24 Hour, Urine.

Necessary Information

24-Hour volume (in milliliters) is required.

Specimen Required

Patient Preparation:

1. If medically feasible, discontinue drugs that release or hinder metabolism of epinephrine, norepinephrine, or dopamine for at least 1 week prior to specimen collection (see Cautions for details). If this is not possible for medical reasons, contact the laboratory to discuss whether a shorter drug-withdrawal period may be acceptable.

2. Unless the reason for testing is drug monitoring, the patient should stop any epinephrine, norepinephrine, or dopamine injections or infusions for at least 12 hours prior to specimen collection. 

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container: Plastic vial

Specimen Volume: 2 mL

Collection Instructions:

1. Add 25 mL of 50% acetic acid as preservative at start of collection. Use 15 mL of 50% acetic acid for children younger than 5 years old. This preservative is intended to achieve a pH of between approximately 2 and 4.

2. Collect urine for 24 hours.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.