5-HIAA

Extra-regional sites: see 5-HIAA, Extra-regional

20 mL aliquot of acidified 24 hour urine collection.  Refer to charts in Specimen Handling and Additional Information sections.

REFRIGERATE during collection.
Urine specimen collection container must have preservative pouch(es) added prior to collection.

Acidify specimen in original collection container.

RECORD 24 hour volume and collection (start and end) dates and time
in the space provided on the requisition.

Mix well and pour off acidified aliquot. 
Sample pH should be less than 3.0.

Collection type	Weight of Sulfamic acid in pouch
24 hour collections for newborn up to 4 years	Use acidification chart in Additional Information section
24 hour and timed  collections for patients > 4 years	7 g pouch in each 4 liter container collection
Random collection available for pediatric (<16) patients only	Refer patient to ACH

Certain foods and medications may interfere. Patient handout available with collection instructions.  See form #CH3008. 

The following drugs cause physiological interference with the levels of urine 5-HIAA:
Physiological decreases: chlorophenylalanine, corticotropin, guanfacine, imipramine, isocarboxazid, isoniazid, levodopa, MAO inhibitors, methyDOPA, moclobemide, octreotide.
Physiological increases: cisplatin, fluorouracil, melphalan, reserpine, rauwolfia.

For Acidification of Pediatric 24 hour Urines:

Age	Number of 0.5 g pouches of Sulfamic acid  to add when Acidifying During Collection
Up to 1 month	Not suitable for 0.5 g pouch. Refer patient to ACH
1 up to 2 months	2
2 up to 4 months	3
4 up to 12 months	4
12 months up to 4 years	5