Ordering Guidance

Random urine collections are preferred for patients with episodic symptoms, eg, in the context of allergic reactions, brought on by specific environmental factors; order NMHR / N-Methylhistamine, Random, Urine.

If the total volume provided is less than 300 mL, this test will be canceled and NMHR ordered and performed.

Necessary Information

Specimen volume (in milliliters) and duration are required.

Specimen Required

Patient Preparation: Patients taking monoamine oxidase inhibitors (MAOIs) may have increased levels of N-methylhistamine. If medically feasible, for 2 weeks before specimen collection, patient should not take MAOIs.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Container/Tube: Plastic, 5-mL tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. No preservative.

3. Aliquot into plastic tube and send at refrigerate temperature.

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