Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (652 page)

   
Normal range:
0.0–15.0 mg/day (24-hour urine); 0.0–14.0 mg/g creatinine.

   Use

   Helps diagnose and monitor treatment for serotonin-secreting carcinoid tumors

   Interpretation

Increased In

   Whipple disease

   Nontropical sprue

   Small increases possible in pregnancy, ovulation, and postsurgical stress

   Various food ingestions (e.g., pineapples, kiwi, bananas, eggplant, plums, tomatoes, avocados, plantains, walnuts, pecans, hickory nuts, coffee)

   Use of certain drugs (e.g., acetanilid, acetaminophen, acetophenetidin, caffeine, coumaric acid, diazepam [Valium], ephedrine, fluorouracil, glyceryl guaiacolate [guaifenesin], heparin, melphalan [Alkeran], mephenesin, methamphetamine, methocarbamol, naproxen, nicotine, Lugol solution, promethazine, phenothiazine, hydroxyl tryptophan)

Decreased In

   Use of certain drugs (e.g., chlorpromazine, promazine, imipramine, isoniazid, monoamine oxidase inhibitors, methenamine, methyldopa, phenothiazines, promethazine)

   Renal insufficiency (possible)

   Limitations

   Foods rich in serotonin and medications, over-the-counter drugs, and herbal remedies that may affect metabolism of serotonin must be avoided at least 72 hours before and during collection of urine for 5-HIAA.