Introduction: Meprobamate (Miltown, Equinil) is a sedative-hypnotic medication that first gained popularity as an anxiolytic and later as a muscle relaxant. It is a major metabolite of the more commonly used muscle relaxant carisoprodol (Soma). In vitro and electroencephalogram studies demonstrated that meprobamate modulates gama-aminobutyric acid (GABA) receptors, similar to barbiturates. Withdrawal from meprobamate manifests in symptoms ranging from mild anxiety to severe autonomic instability and death. Meprobamate is rarely prescribed, but is still given to a small subset of elderly patients.
Clinical findings: In this case of meprobamate withdrawal, the patient initially displayed altered mental status and recurrent seizures resistant to benzodiazepine therapy. Before presentation, the patient complained of several days of malaise, nausea, and tremulousness.
Main diagnoses, therapeutics, interventions, and outcomes: The patient underwent a full work-up, including imaging, a lumbar puncture, a metabolic panel, and collection of additional medication history. These data revealed that the patient’s symptoms were secondary to meprobamate withdrawal. The patient’s seizures failed to resolve with benzodiazepine, but they responded when the patient resumed their usual dose of meprobamate.
Conclusions: Given the potential severity of withdrawal symptoms, diagnosis and proper pharmacologic management is critical for patients suffering from meprobamate withdrawal. A thorough medication history and recognizing withdrawal symptoms are key to diagnosing withdrawal syndromes. Benzodiazepine therapy alone may not sufficiently treat withdrawal seizures, so resumption of meprobamate or treatment with phenobarbital may be required. The same considerations should be made for diagnosis and treatment with carisoprodol, which is metabolized to meprobamate.
Zink, Thomas M. and Erickson, John E.
"A Phantom of the Past: Withdrawal from Meprobamate Presenting with Focal Seizures.,"
Journal of Maine Medical Center: Vol. 2
, Article 11.
Available at: https://knowledgeconnection.mainehealth.org/jmmc/vol2/iss1/11