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Case Reports
. 2018 Jun 25;5(4):380-383.
doi: 10.1002/ams2.351. eCollection 2018 Oct.

Cardiac arrest caused by diphenhydramine overdose

Tomoya Nishino  1 , Shinjirou Wakai  1 , Hiromichi Aoki  1 , Sadaki Inokuchi  1
Affiliations
Case Reports

Cardiac arrest caused by diphenhydramine overdose

Tomoya Nishino et al. Acute Med Surg. .

Abstract

Case: A 45-year-old man presented to our emergency department with disturbance of consciousness; he had mentioned to his family earlier about a drug overdose. When first responders arrived, he suffered cardiac arrest. Cardiac arrest due to drug overdose was diagnosed.The patient was supported with venoarterial extracorporeal membrane oxygenation. Arterial blood gas showed mixed acidosis, and electrocardiogram showed junctional rhythm and complete right bundle branch block.

Outcome: The patient's blood pressure gradually decreased, and he died on the third day of hospitalization. After death, his serum diphenhydramine concentration at the time of arrival was found to be 18.7 μg/mL.

Conclusion: Although diphenhydramine is regarded as a safe medication, it shows dose-dependent toxicity. High intake is associated with death; therefore, caution should be exercised in cases of drug overdose. Developing a procedure for rapid measurement in the emergency department should be a priority.

Keywords: Cardiotoxicity; H1 histamine receptor antagonist; liposoluble; over‐the‐counter drug; venoarterial extracorporeal membrane oxygenation.

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Figures

Figure 1
Figure 1
Electrocardiogram at admission of a 45‐year‐old man with cardiac arrest caused by diphenhydramine overdose. The trace shows junctional rhythm but QTc was unable to be evaluated because of complete right bundle brunch block.
See this image and copyright information in PMC

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