5-HIAA
Label Mnemonic: 5HIAA
Epic Lab Code: LAB352
Downtime Form: A-1a General Laboratory Requisition
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
24 hr Urine More information
Specimen Instructions:
Patients should abstain, if possible, from medications, over-the- counter drugs, and herbal remedies for at least 72 hours prior to the test. Twenty-four hour collections are generally recommended, but random collections may be used. Refrigeration is the most important aspect of specimen preservation.

Foods rich in serotonin (avocados, bananas, eggplant, pineapple, plums, tomatoes, walnuts) and medications that may affect metabolism of serotonin must be avoided at least 72 hours before and during collection of urine for HIAA.
Collection Medium:
Urine - 24 hour/timed plastic urine container
Minimum:
Preferred Minimum: 4 mL aliquot from a well-mixed 24-hour urine. Refrigerate 24-hour specimens during collection.
Rejection Criteria:
Specimen types other than urine.
Turn Around Time:
1-4 days upon receipt at reference laboratory
Reference Range:
5-HIAA, Urine 0.0-15.0 mg/d 5-HIAA, Urine The HIAA-to-creatinine ratio will be reported whenever the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours. 0-14 mg/g crt Creatinine (24-hour) Male 3-8 years: 140-700 mg/d 9-12 years: 300-1300 mg/d 13-17 years: 500-2300 mg/d 18-50 years: 1000-2500 mg/d 51-80 years: 800-2100 mg/d 81 years and older: 600-2000 mg/d Female 3-8 years: 140-700 mg/d 9-12 years: 300-1300 mg/d 13-17 years: 400-1600 mg/d 18-50 years: 700-1600 mg/d 51-80 years: 500-1400 mg/d 81 years and older: 400-1300 mg/d
Interpretive Data:
5-Hydroxyindoleacetic acid (5-HIAA) results are expressed as a ratio to creatinine excretion (mg/ g crt). HIAA mass per day (mg/d) is not reported if the urine collection is random, other than 24 hours, or for a urine volume less than 400 mL/d.
Comments:
Collection containers available from pharmacy.

Note: Foods and medications associated with altered urinary HIAA results:

Decreased HIAA: Aspirin, chlorpromazine (Thorazine), corticotropin, dihydroxyphenylacetic acid, ethanol, gentisic acid, homogentisic acid, hydrazine derivatives, imipramine (Tofranil®), isocarboxazid (Marplan), keto acids, levodopa, MAO inhibitors, methenamine, methyldopa (Aldomet®), perchlorperazine, phenothiazines (Compazine®), promazine, promethazine (Mepergan®).

Increased HIAA: Acetaminophen, acetanilide, caffeine, coumaric acid, diazepam (Valium®), ephedrine, fluorouracil, glycerol guaiacolate (Guaifenesin), melphalan (Alkeran®), mephenesin, methamphetamine (Desoxyn), methocarbamol (Robaxin®), naproxen, nicotine, phenacetin, phenmetrazine, phenobarbital, phentolamine, rauwolfia, reserpine.
Methodology:
Quantitative High Performance Liquid Chromatography - Tandem Mass Spectrometry
CPT Code:
83497