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Serotonin Syndrome Associated with Metaxalone Overdose

  • Toxicology Observation
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Abstract

Introduction

Serotonin syndrome is a potentially life-threatening entity associated with pro-serotonergic medications in therapeutic use, in overdose, or when co-administered with other drugs. A broad range of drugs and drug combinations have been associated with serotonin syndrome. Metaxalone overdose associated with serotonin syndrome has not been previously reported.

Case Report

(Case 1) A 23-year-old female overdosed on tramadol and metaxalone. She developed dysautonomia, diaphoresis, lower extremity rigidity and spontaneous clonus, flaccid upper extremities, and hyperthermia 5 h after ingestion. Her course was complicated by status epilepticus. (Case 2) A 56-year-old female overdosed on metaxalone and was found unresponsive. She developed dysautonomia, lower extremity rigidity and spontaneous clonus, flaccid upper extremities, rhabdomyolysis, acute renal failure, and hyperthermia. Non-depolarizing neuromuscular blockade and cooling blankets were required to control hyperthermia in both cases. Serum metaxalone levels were markedly elevated in both cases.

Conclusion

These are the first reported cases of metaxalone overdose associated with serotonin syndrome, which may be related to monoamine oxidase inhibition.

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Conflict of Interest

The authors have no conflicts of interest to disclose.

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Correspondence to Adam R. Bosak.

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Bosak, A.R., Skolnik, A.B. Serotonin Syndrome Associated with Metaxalone Overdose. J. Med. Toxicol. 10, 402–405 (2014). https://doi.org/10.1007/s13181-014-0404-5

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  • DOI: https://doi.org/10.1007/s13181-014-0404-5

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