What is the mechanism of action and treatment for eucalyptus oil poisoning?

Eucalyptus Oil Poisoning: Mechanism and Treatment

Eucalyptus oil poisoning requires immediate supportive care with focus on airway management, seizure control, and correction of metabolic acidosis—no antidote exists, and activated charcoal or induced emesis should NOT be administered. 1, 2, 3

Mechanism of Action

Eucalyptus oil causes toxicity through multiple pathways when ingested or absorbed systemically:

• Central nervous system depression and excitation: The primary toxic component (1,8-cineole/eucalyptol) causes rapid CNS effects including seizures, ataxia, altered consciousness, and respiratory depression within minutes of exposure 4, 3, 5

• Direct corrosive injury: Eucalyptus oil causes chemical burns to mucous membranes, resulting in damage to the tongue, esophagus, stomach, and intestinal tract 4

• Multi-organ toxicity: Systemic absorption leads to pulmonary emphysema, hepatic macrovesicular steatosis, acute tubular necrosis in kidneys, and severe metabolic acidosis 4, 3, 6

• Dermal absorption: Even topical application can cause systemic toxicity and seizures, particularly in children, demonstrating significant transdermal penetration 5

Immediate First Aid Management

Do NOT administer activated charcoal, ipecac, milk, or water by mouth unless specifically directed by poison control, as these interventions lack evidence and may cause aspiration 1

Critical Initial Steps:

• Contact poison control immediately (US: 1-800-222-1222) for expert guidance on case-specific management 1, 7

• Activate emergency medical services if the patient exhibits seizures, altered consciousness, respiratory symptoms, or cardiovascular instability 1, 4

• For dermal exposure: Remove all contaminated clothing immediately and irrigate skin with copious running water for at least 15 minutes 1, 5

• Airway protection is paramount: Prepare for rapid deterioration with respiratory depression and potential cardiac arrest 4

Hospital-Based Treatment Protocol

Airway and Respiratory Management:

• Provide 100% oxygen to maintain tissue oxygenation 7

• Intubation and mechanical ventilation should be performed promptly if respiratory depression or failure develops 7, 4

• Monitor for pulmonary complications including aspiration pneumonitis and emphysema 4

Seizure Control:

• Administer benzodiazepines as first-line therapy for seizures (standard anticonvulsant protocols apply) 4, 3

• Expect multiple seizure episodes that may persist despite initial treatment 4

Metabolic Acidosis Correction:

• Obtain arterial blood gas analysis immediately to assess for severe metabolic acidosis, which is common in eucalyptus oil poisoning 3

• Administer intravenous sodium bicarbonate for correction of metabolic acidosis 3

• Rapid correction of acidosis is associated with better outcomes and faster recovery 3

Gastrointestinal Management:

• Gastric lavage with normal saline may be considered in patients presenting within 1-2 hours of acute ingestion, though evidence is limited 2

• Administer ranitidine or proton pump inhibitors to prevent vomiting and protect gastric mucosa from corrosive injury 2

• Do NOT induce emesis due to risk of aspiration and worsening CNS depression 1

Cardiovascular Support:

• Establish IV access and provide fluid resuscitation for hemodynamic support 3

• Use vasopressors if hypotension persists despite adequate fluid resuscitation 8

• Prepare for cardiac arrest: CPR may be required in severe cases 4

Renal Monitoring:

• Monitor for rhabdomyolysis with serial creatine kinase levels and urinalysis for myoglobin 6

• Aggressive IV hydration to prevent pigment nephropathy and acute kidney injury 6

• Monitor renal function with serial creatinine and urine output 6

Critical Pitfalls to Avoid

• Never delay supportive care while waiting for toxicology confirmation—clinical presentation is diagnostic 7, 3

• Do not underestimate dermal toxicity: Even topical application as directed can cause seizures, particularly in children 5

• Avoid storage in unmarked containers: Fatal cases have occurred when eucalyptus oil was mistakenly stored in cough syrup bottles 4

• Recognize that adult seizures are uncommon but serious: Unlike children where seizures are expected, adult patients with seizures indicate severe poisoning 3

Disposition and Monitoring

• ICU admission is mandatory for all symptomatic patients with seizures, altered consciousness, or metabolic acidosis 3

• Minimum 24-hour observation period even for asymptomatic patients after confirmed ingestion 2

• Most patients recover within 3-4 days with appropriate supportive care 3

• Mortality can occur despite aggressive treatment, particularly with large ingestions causing multi-organ failure 4