Sympathomimetic Toxicity Treatment & Management

Updated: Mar 02, 2021
  • Author: Paul Kolecki, MD, FACEP; Chief Editor: Asim Tarabar, MD  more...
  • Print

Approach Considerations

Managing the airway and controlling agitation are the two main prehospital treatment concerns. Many patients with sympathomimetic poisoning present in an agitated state and may require physical and/or chemical restraint. A rapid bedside blood glucose test should be performed to rule out hypoglycemia. Hypoglycemia should be treated if detected.

General supportive care is the main treatment measure for sympathomimetic toxicity because no antidote exists. Immediate assessment of the airway, breathing, and circulation is recommended, followed by continuing close monitoring of vital signs. Benzodiazepines remain the initial agent of choice to treat sympathomimetic-induced tachycardia, agitation, seizures, hypertension, and hyperthermia.

If inpatient care is required, it should be under the direction of a medical toxicologist or a physician with expertise in critical care.


Emergency Department Care

Sympathomimetic toxicity is frequently associated with significant agitation, thus necessitating the use of physical restraints and chemical sedation. However, physically restrained patients with sympathomimetic-associated agitation or hyperthermia have an associated significant risk of sudden death. If physical restraints are necessary, the rapid and liberal use of chemical sedation to control agitation is strongly recommended. Benzodiazepines (eg, diazepam) are the safest first approach in calming sympathomimetic-poisoned patients. They should be administered frequently in titrated doses.

Consider gastric decontamination for oral ingestions of sympathomimetic agents. Gastric decontamination is associated with subsequent vomiting and aspiration, so airway control is strongly recommended prior to any gastric decontamination. In addition, the patient's airway, breathing, circulation, and agitation should be stabilized beforehand.

Measurement of the core temperature of sympathomimetic poisoned patients is imperative. If hyperthermia is present, standard cooling measures should be initiated. Controlling agitation significantly helps in cooling a hyperthermic patient.

Hypertension unresponsive to sedation should be treated with a rapidly acting and easily titrated agent (eg, nicardipine).

Seizures should be promptly controlled with benzodiazepines and/or barbiturates. Obtaining a CT scan of the brain for all sympathomimetic toxic patients who seize, develop a focal neurologic deficit, or experience a severe headache with or without accompanying hypertension is recommended.

Consider psychiatric evaluation before discharging patients from the hospital. Most patients with sympathomimetic toxicity who remain asymptomatic after 6 hours postingestion may be medically discharged; however, patients who have ingested long-acting preparations typically should be monitored for 24 hours. Most of these patients are admitted to a telemetry floor or an intensive care unit. 



Synthetic cathinones

The toxicologic effects of synthetic cathinones mimic those of the amphetamines and MDMA, and treatment is primarily supportive, focusing on management of the agitation, fever, hyponatremia, and end-organ complications that can occur with these agents. The main adverse effects are cardiovascular (hypertension, tachycardia, angina, myocarditis) and neuropsychiatric (agitation, aggression, dystonia, and hyperreflexia). Hyponatremia may result in cerebral edema and death, and should be managed like MDMA-related hyponatremia, with fluid restriction for mild cases and hyperosmotic agents for cerebral edema. [12]  

For a patient with MDMA-induced severe hyponatremia, a rapid increase in serum sodium by 4 - 6 mEq/L (4-6 mmol/L) is recommended. This is customarily accomplished by prompt administration of a 100 ml IV bolus of 3% sodium chloride (hypertonic saline) over 10 minutes.



Consultation from the regional poison control center or a local medical toxicologist (certified by the American Board of Medical Toxicology and/or the American Board of Emergency Medicine) for additional information and patient care recommendations is recommended.

Prolonged critical care management often is required for the numerous complications that may occur with severe overdose (eg, hyperthermia, seizures, acute respiratory distress syndrome [ARDS], acute kidney injury, rhabdomyolysis, central nervous system dysfunction).