- Michael Bodmer, MD, MSc
Michael Bodmer, MD, MSc
- Division of General Internal Medicine
- Bern University Hospital, Inselspital, Bern, Switzerland
- Pharmacoepidemiology Unit, Pharmaceutical Sciences
- University Hospital Basel, Switzerland
- Alessandro Ceschi, MD
Alessandro Ceschi, MD
- Head Division of Science
- Swiss Toxicological Information Centre, Associated Institute of the University of Zurich
- Department of Clinical Pharmacology and Toxicology
- University Hospital Zurich, Switzerland
- Section Editor
- Stephen J Traub, MD
Stephen J Traub, MD
- Section Editor — Toxicology
- Associate Professor of Emergency Medicine
- Mayo Medical School
- Deputy Editor
- Jonathan Grayzel, MD, FAAEM
Jonathan Grayzel, MD, FAAEM
- Senior Deputy Editor — UpToDate
- Deputy Editor — Emergency Medicine (Adult and Pediatric)
- Deputy Editor — Primary Care Sports Medicine (Adolescents and Adults)
- Assistant Professor of Emergency Medicine
- University of Massachusetts Medical School
Meprobamate is a sedative and anxiolytic medication that was marketed for decades in the United States and continues to be used in Europe. The first case of meprobamate poisoning was described in 1956 . Due to its substantial abuse potential, meprobamate is no longer recommended for treatment of insomnia and has been replaced by benzodiazepines and other agents. Although use of the drug is declining, significant meprobamate overdose remains a life-threatening emergency.
This topic will review the basic pharmacology, clinical presentation, and management of meprobamate poisoning. Discussions of the general approach to the management of poisoned patients and detailed management of other toxins are found elsewhere. (See "General approach to drug poisoning in adults" and "Initial management of the critically ill adult with an unknown overdose".)
Meprobamate poisoning is rare and most cases involve suicide attempts . In France, meprobamate has been used more widely and the drug was involved in approximately 7 percent of psychotropic poisonings in 2005 . Mortality in cases of overdose has ranged between 1.7 and 5 percent [4-6]. Meprobamate ingestion is associated with an increased risk of intensive care unit (ICU) admission (adjusted odds ratio [OR] = 2.71; 95% CI: 1.27-5.81) .
Meprobamate is a carbamate which acts primarily as a sedative by increasing GABAA-mediated neurotransmission in a manner similar to barbiturates [8,9]. Carisoprodol, prescribed as a centrally acting muscle relaxant, is mainly metabolized to meprobamate by cytochrome P450 2C19, shares properties with meprobamate, and also has significant potential for abuse [10-12].
PHARMACOKINETICS AND TOXICOKINETICS
After oral ingestion of a therapeutic dose, meprobamate is rapidly absorbed from the gastrointestinal tract and peak plasma concentrations are reached within one to three hours [13,14]. Protein binding is negligible (14 to 24 percent). The drug’s volume of distribution is reported to be 0.70 L/kg, and is not significantly altered in overdose. A standard single therapeutic dose for an adult ranges from 200 to 800 mg. Significant toxicity is likely with ingestions of 4 to 5 g or more [3,4].To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
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- Reeves RR, Carter OS, Pinkofsky HB, et al. Carisoprodol (soma): abuse potential and physician unawareness. J Addict Dis 1999; 18:51.
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- Verpooten GA, De Broe ME. Prediction of the efficacy of hemoperfusion and hemodialysis in severe poisoning. Arch Toxicol Suppl 1982; 5:304.
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- Micromedex Healthcare Series. Thomson Reuters, Greenwood Village, Colorado, 2010.
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- Bourry J, Sainty JM, Roux JJ, Ressiot G. [Acute pancreatitis in the course of meprobamate poisoning. Possible role of pressor amine therapy]. Nouv Presse Med 1976; 5:1918.
- Fathallah N, Zamy M, Slim R, et al. Acute pancreatitis in the course of meprobamate poisoning. JOP 2011; 12:404.
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- Lin JL, Lim PS, Lai BC, Lin WL. Continuous arteriovenous hemoperfusion in meprobamate poisoning. J Toxicol Clin Toxicol 1993; 31:645.
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- PHARMACOKINETICS AND TOXICOKINETICS
- CLINICAL FEATURES OF OVERDOSE
- Clinical symptoms and signs
- - Overview
- - Cardiovascular
- - Neurologic
- - Respiratory
- - Other manifestations
- DIAGNOSTIC IMAGING
- LABORATORY EVALUATION
- Testing for meprobamate
- General evaluation
- DIFFERENTIAL DIAGNOSIS
- Initial stabilization
- Treatment of hypotension
- Gastrointestinal decontamination
- Enhanced elimination
- Ongoing treatment and disposition
- ADDITIONAL RESOURCES
- SOCIETY GUIDELINE LINKS
- SUMMARY AND RECOMMENDATIONS