Cook, Matthew D, DO

Nappe, Thomas M, DO

Surmaitis, Ryan M, DO

English

Lehigh Valley Health Network: LVHN Scholarly Works

Serotonin Syndrome Associated with Therapeutic Metaxalone in a Patient with Cirrhosis.

Lehigh Valley Health NetworkLVHN Scholarly WorksDepartment of Emergency MedicineSerotonin Syndrome Associated With TherapeuticMetaxalone Dosing in a Patient With CirrhosisRyan M Surmaitis DOLehigh Valley Health Network, Ryan.Surmaitis@lvhn.orgThomas M. Nappe DOLehigh Valley Health Network, Thomas_M.Nappe@lvhn.orgMatthew D. Cook DOLehigh Valley Health Network, Matthew_D.Cook@lvhn.orgFollow this and additional works at: http://scholarlyworks.lvhn.org/emergency-medicinePart of the Emergency Medicine CommonsThis Poster is brought to you for free and open access by LVHN Scholarly Works. It has been accepted for inclusion in LVHN Scholarly Works by anauthorized administrator. For more information, please contact LibraryServices@lvhn.org.Published In/Presented AtSurmaitis, R., Nappe, T., Cook, M., (2015, October 10). Serotonin Syndrome Associated With Therapeutic Metaxalone Dosing in a PatientWith Cirrhosis. Poster presented at: North American Congress of Clinical Toxicology/NACCT (Annual meeting affiliated with AACT,the American Academy of Clinical Toxicology), San Francisco, CA.Lehigh Valley Health Network, Allentown, PennsylvaniaRyan M. Surmaitis, DO; Thomas M. Nappe, DO; Matthew D. Cook, DOBackgroundSerotonin Syndrome Associated With Therapeutic Metaxalone Dosingin a Patient With CirrhosisDiscussion:© 2015 Lehigh Valley Health NetworkMetaxalone has recently been associated with serotonin syndrome (SS) in the setting of overdose. We report the first case of SS with therapeutic metaxalone dosing in a cirrhosis patient.Case ReportA 65-year-old male presented to the ED with altered mental status. He was recently prescribed metaxalone (800mg every 12 hours) for a back injury. Family reported within one hour of each ingestion the patient developed confusion, diaphoresis, facial flushing, and muscle stiffness. Symptoms would gradually improve over several hours but then worsen with each subsequent dose. Medical history included cirrhosis, depression, and thrombocytopenia. Home medications included venlafaxine, quetiapine, propranolol, and rifaximin.Initial vital signs were BP of 154/62, HR of 78, RR of 20, temperature of 38.2 C, and oxygen saturation of 94%. The patient was confused, agitated, and profusely diaphoretic. Patient had ocular clonus, mydriasis, hyper-rigidity and sustained clonus of the lower extremities. Lab values showed platelets 114 thou/cmm, creatinine 1.68 mg/dl, lactate 3.2  mmol/L, ammonia 90 umol/L, normal aminotransferases, and a negative urine drug screen. EKG showed normal sinus rhythm. Computed tomography of the head showed no abnormality. Metaxalone level, drawn approximately 12 hours after last dose, was 11mcg/ml (peak plasma concentrations average 1.7mcg/mL three hours after 800mg dose).The patient was intubated for airway protection using etomidate and rocuronium. Diagnosis of SS was suspected. Fentanyl was started for sedation, however, this was replaced Metaxalone, a 2-oxazolidinone, has been theorized to have reversible MAOI properties at elevated concentrations. Previously reported cases involve overdoses of metaxalone as a single drug or in combination with another pro-serotonergic agent. This is the first case of SS in therapeutic metaxalone dosing with a confirmed serum concentration.Metaxalone primarily undergoes hepatic metabolism although the impact of hepatic disease on the pharmokinetics of metaxalone has not been established. We propose that cirrhosis led to decreased elimination of metaxalone and an elevated serum concentration. Supratherapeutic metaxalone serum concentrations combined with a SNRI triggered SS.ConclusionHepatic insufficiency may lead to accumulation of serum metaxalone. At high concentrations or when combined with another pro-serotonergic agent this can lead to SS.with midazolam. Hyperthermia resolved after intubation without antipyretics. Serotongeric symptoms gradually improved over several days. The patient had a prolonged hospital course complicated by GI bleeding and hepatorenal syndrome.

Serotonin Syndrome Associated With Therapeutic Metaxalone Dosing in a Patient With Cirrhosis

https://scholarlyworks.lvhn.org/cgi/viewcontent.cgi?article=1345&context=emergency-medicine

Serotonin Syndrome Associated With Therapeutic Metaxalone Dosing in a Patient With Cirrhosis

Abstract

Similar works

Full text

Available Versions

Lehigh Valley Health Network: LVHN Scholarly Works

Lehigh Valley Health Network: LVHN Scholarly Works