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. 2023 Aug 12;17(1):39-42.
doi: 10.2478/abm-2023-0042. eCollection 2023 Feb.

A case of diphenhydramine intoxication showing prolonged false positive tricyclic antidepressant in the urine assay

Dongsun Kim  1 , Hyun Young Shin  2 , Bon D Ku  3
Affiliations

A case of diphenhydramine intoxication showing prolonged false positive tricyclic antidepressant in the urine assay

Dongsun Kim et al. Asian Biomed (Res Rev News). .

Abstract

Background: The urine immunochromatographic assay is a useful screening tool for patients suspected of acute drug intoxication in emergency conditions. Diphenhydramine intoxication shows symptoms similar to those of tricyclic antidepressant (TCA) intoxication.

Case presentation: We examined a case of diphenhydramine intoxication showing cerebellar ataxia and prolonged false positive results for TCA in the urine. The urine TCA test showed persistently positive results even 60 h after the patient's initial drug screening. We observed negative conversion 90 h after the initial drug screening.

Discussion: Considering the similarities of clinical symptoms between diphenhydramine and TCA intoxication, emergency physicians should consider the possibility of cross-reactivity in the diagnosis of a patient with unknown acute drug intoxication showing positive results of TCA immunochromatographic assay in the urine.

Conclusion: The present case suggests that diphenhydramine overdose may cause cerebellar ataxia and show prolonged cross-reactivity as TCA in the urine.

Keywords: ataxia; cross reactivity; diphenhydramine; tricyclic antidepressants; urine immunochromatographic assay.

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Figures

Figure 1.
Figure 1.
The chemical structure of dephenhydramine (A), imipramine (B) and the common substructure of dephenhydramine and imipramine (C). The similarities are as follow: AP Tanimoto: 0.421642, MCS Tanimoto: 0.2500, MCS Size: 8 and SMILES of common substructure: C(C)c1ccccc1. AP, atom pairs; MCS, maximum common substructure; SMILES, simplified molecular-input line-entry system.
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References

    1. Pragst F, Herre S, Bakdash A. Poisonings with diphenhydramine – a survey of 68 clinical and 55 death cases. Forensic Sci Int. 2006;161:189–97. - PubMed
    1. Clark RF, Vance MV. Massive diphenhydramine poisoning resulting in a wide-complex tachycardia: successful treatment with sodium bicarbonate. Ann Emerg Med. 1992;21:318–21. - PubMed
    1. Jang DH, Manini AF, Trueger NS, Duque D, Nestor NB, Nelson LS, Hoffman RS. Status epilepticus and wide-complex tachycardia secondary to diphenhydramine overdose. Clin Toxicol (Phila) 2010;48:945–8. - PMC - PubMed
    1. Ros JJ, Pelders MG. Amanda JJ, Bruce AG. On-site drug testing (Forensic Science and Medicine) Totowa: Humana Press; 2002. AccuSign drugs of abuse test; pp. 111–21.
    1. Backman TW, Cao Y, Girke T. ChemMine tools: an online service for analyzing and clustering small molecules. Nucleic Acids Res. 2011;3:W486–91. - PMC - PubMed

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