Cihangir Buyukgoz, MD
University of Tennessee Le Bonheur Children's Hospital
Memphis
Disclosure information not submitted.
Shantaveer Gangu, MD
Pediatric Intensivist
University of Tennessee Le Bonheur Children's Hospital, United States
Disclosure information not submitted.
Dai Kimura, MD
Pediatric Intensivist
Methodist Le Bonheur Childrens Hospital, United States
Disclosure information not submitted.
Title: Successful Treatment of Comatose Patient due to Cyclobenzaprine Overdose with Plasma Exchange
Case Report Body:
Introduction: Intentional ingestions in adolescents are common reasons for morbidity and mortality and can potentially have serious complications. These patients require prompt evaluation and stabilization with a poison control center consultation. After initial stabilization, type and amount of substance ingested should be considered, and appropriate treatment should be provided. We present an adolescent patient who ingested acetaminophen and cyclobenzaprine, a muscle relaxing agent that has no known existing antidote, presenting in coma treated with therapeutic plasma exchange (TPE).
Description: 15-year-old female with history of major depression disorder was found unresponsive by her parents. Initial evaluation revealed Glasgow Coma Scale of 3 and oxygen saturation of 80% on room air therefore she was intubated. Parents reported that she could have taken acetaminophen and cyclobenzaprine. Initial diagnostic evaluation was remarkable for increased acetaminophen level (270 mcg/ml) with respiratory acidosis. Her physical exam was remarkable for nonreactive pupils, and no brainstem reflexes including cough, gag, and corneal reflexes after admission to the intensive care unit. Poison control center only suggested supportive care. Since there is supporting literature on the use of TPE for amitriptyline, structurally similar to cyclobenzaprine, decision was made to perform TPE. TPE was performed with 1.5 times blood volume exchange and soon after the treatment cough reflex improved with other brainstem reflexes gradually within next 48 hours, and she was extubated.
Cyclobenzaprine levels were reported one week later as 110 ng/ml and 36 ng/ml pre- and post-TPE treatment, respectively. In the meantime, she also completed NAC treatment and her acetaminophen level decreased with liver enzymes remaining normal. She had no neurological dysfunction when she was discharged from our hospital.
Discussion: Cyclobenzaprine overdose has multiple life-threatening complications including respiratory failure, cardiac arrest, arrhythmia, and seizures. It has a long elimination half-life of 32h with high protein binding properties (93%) which makes TPE a viable treatment option. Urgent TPE is an effective treatment for severe cyclobenzaprine overdose even with its large volume of distribution.