What is the management approach for suspected caffeine toxicity?

Management of Caffeine Toxicity

The management of caffeine toxicity should follow a stepwise approach prioritizing supportive care with benzodiazepines as first-line treatment for agitation and cardiovascular symptoms, followed by targeted interventions for specific complications. 1

Clinical Presentation

Caffeine toxicity presents with a spectrum of symptoms depending on serum levels:

• Mild to moderate toxicity: Tachycardia, hypertension, agitation, tremor, insomnia, diuresis, gastrointestinal distress
• Severe toxicity (serum levels >50 mg/L): Hypotension, cardiac arrhythmias, seizures, hypokalemia, hyponatremia, metabolic acidosis, rhabdomyolysis, respiratory failure
• Life-threatening toxicity (serum levels >100 mg/L): Ventricular fibrillation, circulatory collapse, death 2, 3

Initial Management

1. Airway, Breathing, Circulation

   • Secure airway if decreased consciousness
   • Provide supplemental oxygen as needed
   • Establish IV access for fluid resuscitation

2. Decontamination

   • Consider activated charcoal if presentation is within 1-2 hours of ingestion
   • Do not induce emesis

3. Benzodiazepines

   • First-line treatment for agitation, tachycardia, hypertension, and seizures
   • Start with 2 mg IV midazolam (benzodiazepine-naïve patients) followed by 1 mg/h infusion if needed 1
   • For breakthrough agitation, administer bolus doses of 1-2× hourly infusion rate every 5 minutes

Cardiovascular Management

1. Hypotension

   • IV fluid resuscitation
   • Vasopressors (norepinephrine or epinephrine) for refractory hypotension 4

2. Arrhythmias

   • Sodium bicarbonate for wide-complex tachycardia (similar to management for sodium channel blockade) 4
   • Consider amiodarone 300 mg IV bolus for ventricular fibrillation 3
   • Avoid β-blockers as they may worsen hypotension 1

3. Electrolyte Management

   • Aggressive potassium replacement for hypokalemia (critical for preventing and treating arrhythmias) 3
   • Monitor and correct sodium, magnesium, and calcium abnormalities

Specific Interventions for Severe Toxicity

1. Seizure Management

   • Benzodiazepines are first-line (IV diazepam or lorazepam)
   • Consider barbiturates (pentobarbital) for refractory seizures 2

2. Hyperthermia Management

   • Rapid external cooling is highest priority for life-threatening hyperthermia
   • Use evaporative or immersive cooling methods 1

3. Enhanced Elimination

   • Hemodialysis for severe cases with hemodynamic instability, refractory seizures, or extremely high caffeine levels 5
   • Consider VA-ECMO for circulatory support in patients with refractory ventricular fibrillation 5

Monitoring

• Continuous cardiac monitoring
• Frequent vital signs
• Serial electrolyte measurements (especially potassium)
• Consider serum caffeine levels if available (toxic >50 mg/L, potentially lethal >100 mg/L) 2, 6
• Monitor for rhabdomyolysis with CK levels

Special Considerations

• Drug Interactions: Caffeine metabolism occurs via CYP1A2. Medications that inhibit this enzyme (fluvoxamine, certain quinolones, mexiletine) can potentiate caffeine toxicity 7
• Disposition: Patients with significant symptoms require admission for monitoring; asymptomatic patients with potentially toxic ingestions should be observed for at least 6 hours

Common Pitfalls to Avoid

• Failing to recognize caffeine as the toxin (consider in patients with unexplained tachycardia, agitation, and seizures)
• Inadequate potassium replacement (critical for preventing fatal arrhythmias) 3
• Using β-blockers for tachycardia (may worsen hypotension)
• Delaying hemodialysis in severe cases with hemodynamic instability
• Underestimating the potential lethality of caffeine overdose (fatal doses typically exceed 5g but can be lower) 6

In summary, management of caffeine toxicity requires prompt recognition, supportive care with benzodiazepines, aggressive electrolyte management, and consideration of enhanced elimination techniques for severe cases.