Ryanodex is being investigated as a potential adjuvant treatment for people suffering from psychostimulant drug-induced toxicity (PDIT), a life-threatening medical condition that results mainly from the abuse of certain illicit drugs, most notably methamphetamine, and related forms (MDMC or "Molly"; MDMA or "Ecstasy"). Ryanodex is approved for the treatment of malignant hyperthermia in conjunction with appropriate supportive measures and for prevention of malignant hyperthermia in patients at high risk and in this study, will be investigated for the treatment of PDIT. The hypothesis of this study is that administration of Ryanodex as adjuvant treatment to Standard of Care (SOC) will improve the clinical outcome compared with SOC alone, in subjects with psychostimulant drug induced toxicity. Current SOC is defined as body cooling and supportive measures.