Management of Adrenaline (Epinephrine) Overdose
Adrenaline overdose requires immediate supportive care with rapid-acting alpha-blockers (phentolamine) for hypertensive crisis, beta-blockers (propranolol) for arrhythmias, and vasodilators (nitrites) for severe hypertension, while maintaining continuous hemodynamic monitoring. 1
Immediate Recognition and Assessment
Epinephrine overdose presents with a characteristic rapid onset of:
- Severe hypertension (potentially causing cerebrovascular hemorrhage, especially in elderly patients)
- Tachycardia preceded by transient bradycardia
- Cardiac arrhythmias including premature ventricular contractions (appearing within 1 minute), multifocal ventricular tachycardia, and atrial tachycardia with possible AV block
- Extreme pallor and coldness of skin
- Agitation, anxiety, tremor, and severe headache
- Pulmonary edema (from peripheral vasoconstriction combined with cardiac stimulation)
- Myocardial ischemia/infarction and cardiomyopathy 1, 2, 3
Critical pitfall: In pediatric patients, signs of epinephrine overdose can be indistinguishable from progressive anaphylactic shock until blood pressure is measured. Blood pressure measurement is essential to differentiate overdose from shock 4.
Primary Treatment Algorithm
1. For Hypertensive Crisis and Pulmonary Edema
- Phentolamine (rapidly acting alpha-adrenergic blocker): 0.1-0.2 mg/kg up to 10 mg diluted in 10 mL of 0.9% sodium chloride 5, 1
- Provide respiratory support as needed for pulmonary edema
- Administer diuretics if pulmonary edema develops 3
2. For Cardiac Arrhythmias
- Propranolol (beta-adrenergic blocker) for ventricular arrhythmias and tachycardia 1
- Continuous ECG monitoring is mandatory
3. For Persistent Severe Hypertension
- Rapidly acting vasodilators (nitrites) if alpha-blockers are insufficient 1
- Titrate to blood pressure response
4. For Prolonged Hypotension (if occurs after treatment)
- May require administration of another pressor drug 1
- This is uncommon but can follow aggressive vasodilator therapy
Supportive Care Measures
- Continuous hemodynamic monitoring is essential throughout treatment
- Mechanical ventilation if acute cardiorespiratory failure develops 3
- Low-dose inotropes may be needed in cases of ischemic heart failure 3
- Monitor for metabolic acidosis (elevated lactic acid), renal insufficiency 1
- Serial cardiac biomarkers to assess for myocardial necrosis 2
Key Clinical Context
The evidence shows that epinephrine is rapidly inactivated in the body, making treatment primarily supportive 1. Case reports demonstrate that even severe overdoses (such as 5 mg IV instead of nebulized, or 10-fold overdoses) can result in full recovery without sequelae when managed appropriately with the above interventions 2, 3.
Common iatrogenic causes include:
- Confusion between 1:1000 (1 mg/mL) and 1:10,000 (0.1 mg/mL) concentrations 5
- IV administration of doses intended for IM/nebulized routes 2, 3
- Dose calculation errors, particularly in pediatrics 4, 3
Prevention Strategies
While not directly treating overdose, the evidence strongly supports system-level interventions:
- Stock prefilled, appropriately labeled IM epinephrine syringes that are easily distinguished from IV preparations 6
- Implement standardized drug order forms 3
- Use epinephrine autoinjectors when appropriate to reduce dosing errors 7
Duration of monitoring: Patients require continuous observation for at least several hours, as complications can be life-threatening but typically resolve within 24 hours with appropriate management 2, 3.