title: Severe Carisoprodol Withdrawal After a 14-Year Addiction and Acute Overdose.
abstract: BACKGROUND
  Carisoprodol, a centrally acting muscle relaxant with a high abuse potential, has barbiturate-like properties at the GABA-A receptor, leading to central nervous system depression and desired effects. Its tolerance and dependence has been previously demonstrated in an animal model, and withdrawal has been described in several recent case reports. Many cases can be effectively managed with a short course of benzodiazepines or antipsychotic agents. However, abrupt cessation in a patient with a history of long-term and high-dose carisoprodol abuse may result in symptoms that are more difficult for providers to treat.
  
  
  METHODS
  We present a case of a 34-year-old man with a long history of carisoprodol abuse who was found unresponsive after having ingested 7.5 grams of carisoprodol. He was intubated and admitted to the intensive care unit. He was given propofol, dexmedetomidine, fentanyl, ketamine, lorazepam, midazolam, quetiapine, and haloperidol, some at high-dose infusions, before his agitation and ventilator asynchrony could be controlled. His improvement coincided with the addition of carisoprodol and phenobarbital to his treatment regimen. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Trends show increasing emergency department presentations for drug-related disorders and treatment. This case highlights an uncommon case of carisoprodol withdrawal that may be encountered by emergency physicians, and demonstrates that benzodiazepines may not be sufficient to suppress severe withdrawal symptoms. Treatment with carisoprodol and phenobarbital provided additional benefit and can be considered in cases of severe carisoprodol withdrawal.
authors.affiliation: Department of Emergency Medicine, University of California, San Francisco, San Francisco, California; California Poison Control System, San Francisco Division, San Francisco, California.
authors.forename: Kathy T
authors.initials: KT
authors.lastname: Vo
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco, San Francisco, California.
authors.forename: Howard
authors.initials: H
authors.lastname: Horng
authors.affiliation: Department of Emergency Medicine, University of California, San Francisco, San Francisco, California; California Poison Control System, San Francisco Division, San Francisco, California.
authors.forename: Craig G
authors.initials: CG
authors.lastname: Smollin
authors.affiliation: California Poison Control System, San Francisco Division, San Francisco, California; Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, California.
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
mesh_terms: D000328:Adult; D002328:Carisoprodol / Q000009:adverse effects*; D020927:Dexmedetomidine / Q000494:pharmacology / Q000627:therapeutic use; D062787:Drug Overdose / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D005283:Fentanyl / Q000494:pharmacology / Q000627:therapeutic use; D006220:Haloperidol / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology / Q000627:therapeutic use; D007362:Intensive Care Units / Q000458:organization & administration; D007649:Ketamine / Q000494:pharmacology / Q000627:therapeutic use; D008140:Lorazepam / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008874:Midazolam / Q000494:pharmacology / Q000627:therapeutic use; D015742:Propofol / Q000494:pharmacology / Q000627:therapeutic use; D000069348:Quetiapine Fumarate / Q000494:pharmacology / Q000627:therapeutic use; D012121:Respiration, Artificial / Q000379:methods; D013375:Substance Withdrawal Syndrome / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy*; D019966:Substance-Related Disorders / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy
chemical_list: D006993:Hypnotics and Sedatives; D002328:Carisoprodol; D000069348:Quetiapine Fumarate; D020927:Dexmedetomidine; D007649:Ketamine; D006220:Haloperidol; D008140:Lorazepam; D008874:Midazolam; D005283:Fentanyl; D015742:Propofol
keywords: addiction; carisoprodol; withdrawal