This skeletal muscle relaxant has been implicated in causing serotonin toxicity in overdose?
Martini DI et al. report two cases of metaxolone overdose resulting in serotonin syndrome in patients on therapeutic doses of SSRIs. Metaxolone causes serotonin toxicity secondary to MAO Inhibition. (Martini DI et al. Serotonin syndrome following metaxalone overdose and therapeutic use of a selective serotonin reuptake inhibitor. Clinical Toxicology 2015; 53(3): 185-187.)