Massive suicidal ingestion of caffeine: a case report with investigation of the cardiovascular effect/concentration relationships.

BACKGROUND

Caffeine poisoning may cause life-threatening arrhythmias and hemodynamic failure. We aimed to investigate the toxicokinetics (TK), toxicodynamics (TD) and TK/TD relationships of caffeine in a case of poisoning.

CASE REPORT: A 47-year-old male ingested pure anhydrous caffeine powder (70 g) in a suicide attempt. He developed agitation, tachycardia, and two episodes of ventricular fibrillation treated with defibrillation and tracheal intubation. He was successfully managed using intravenous infusions of esmolol and norepinephrine.

METHODS

We modelled the time-course of plasma caffeine concentration (TK study using online liquid chromatography-tandem mass spectrometry), the time-course of blood lactate concentration and infusion rates of esmolol and norepinephrine (TD studies) and the TK/TD relationships.

RESULTS

Caffeine TK was of first-order peaking at 258 mg/L with an elimination half-life of 46.2 h and clearance of 2.2 L/h. Caffeine-related effects on blood lactate (peak, 10 mmol/L at 1.25 h postingestion) were described by a Bateman-type equation (formation rate, 0.05 mmol/mg.h; elimination rate, 0.9 mmol/mg.h). Esmolol and norepinephrine infusion rates to reverse caffeine-related cardiovascular effects (peaks at 51-h postingestion) fitted well with a sigmoidal Emax model (EC50, 180.0 and 225.9 mg/L, respectively; Hill coefficient, 10.0).

CONCLUSION

Massive caffeine ingestion is characterized by prolonged caffeine elimination. TK/TD relationships are helpful to quantify caffeine-related catecholaminergic effects.