Sola Dosis Facit Venenum: Understanding Severity of TCA Intoxication

The Dose Makes the Poison, or does it? Judicious Management of TCA Intoxication. Author(s): Sean Brachvogel, MD, MPH; Justin Osborn, MD; Tanya Page, MD Context/background: Tricyclic antidepressants (TCAs) have been mostly supplanted by SSRIs in the treatment of depression, however they remain a mainstay of chronic pain management.1 Untreated suicide attempts with a TCAs carry a 70% fatality rate, which drops dramatically to 3% with hospitalization.2 As such, maintaining healthcare provider recognition and management of TCA toxicity is of lifesaving importance. Objective: Here we describe a case report in which alcohol ingestion masked the severity of an accidental TCA overdose, and we reflect on a common diagnostic approach. Case Report: Our discussion begins with a 68-year-old Caucasian female with a history of COPD, diverticulitis, HLD, HTN, and chronic pain who presents with 80 minutes of altered mental status after consuming alcohol and her regularly prescribed amitriptyline. Her EKG demonstrated QRS widening and her serum alcohol level was 217. She was diagnosed with TCA overdose and alcohol intoxication and was treated with a sodium bicarbonate drip. Management of her TCA intoxication was clouded by a background of significant alcohol intoxication, and an amitriptyline and nortriptyline levels were collected to elucidate the severity of the TCA overdose. After eight hours of bicarbonate infusion her QRS narrowed and her condition stabilized. Conclusions: TCA therapy is common and TCA overdose is both especially dangerous and treatable. In our case, collecting amitriptyline and nortriptyline levels did not aid in our diagnosis or treatment. We conclude that EKGs are the superlative diagnostic modality when evaluating suspected TCA overdoses. References: Meloy, Patrick, et al. “Tricyclic Antidepressant Overdose.” UC Irvine Journal of Teaching in Emergency Medicine, 2019, escholarship.org/content/qt196242gj/qt196242gj.pdf?t=pwuyer. Tsai, Vivian, and David Vaerrier. “Tricyclic Antidepressant Toxicity.” Practice Essentials, Pathophysiology, Epidemiology, 17 Mar. 2020, emedicine.medscape.com/article/819204-overview#a6.https://digitalcommons.psjhealth.org/milwaukie_family/1002/thumbnail.jp