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

Abstract

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 E_max 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.

Keywords:

• Caffeine
• poisoning
• toxicokinetics
• toxicodynamics
• esmolol
• norepinephrine

Acknowledgment

The authors thank Mrs. Alison Good (Scotland, UK) for her helpful review of the manuscript.

Author contributions

Study concept and design by Vincent Grémain and Bruno Mégarbane. Patient management by Vincent Grémain and Guillaume Schnell. Toxicological analysis by Elodie Saussereau. Modelling by Lucie Chevillard. Analysis and interpretation of data by all authors. Drafting the manuscript by Vincent Grémain and Bruno Mégarbane. Critical revision of the manuscript for important intellectual content by all authors.

Disclosure statement

The authors report no conflict of interest. The authors alone are responsible for the content and writing of this paper. The manuscript has been read and approved by all authors. The authors certify that the submission is not under review at any other publication. The authors certify that the authors have no other submissions and previous reports that might be regarded as overlapping with the current work. The authors declare no financial disclosures.