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'Sweet Dreams', 'Happy Days' and elevated 24-h urine 5-hydroxyindoleacetic acid excretion
Magnus Lars Peter Hallin1, Kamala Mahmoud, Ananth Viswanath
1Department of Clinical Chemistry, New Cross Hospital, Wolverhampton, West Midlands WV10 0QP. magnus.hallin@nhs.net
Abstract:
We report two patients with markedly elevated 24-h urine 5-hydroxyindoleacetic acid (5-HIAA) excretion due to over-the-counter (OTC) self-medication with 5-hydroxytryptophan (5-HTP). It is important to recognize that OTC medication may cause increased 'false-positive' 5-HIAA excretion to prevent undue patient anxiety and unnecessary further investigation for carcinoid disease. Discordance between chromogranin A and 24-h urine 5-HIAA results should alert to the possibility of false-positive or -negative laboratory results.
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