Lethal diltiazem poisoning

A 60-year-old man presented to an emergency department 2 h after the ingestion of 8 g of diltiazem (about 40 slow-release capsules, 200 mg/each) in a suicide attempt. The subject was treated with a gastric lavage and activated charcoal; then, a temporary transvenous pacing was also inserted. Despite emergency pharmacological treatment, the subject died about 20 h after ingestion. Postmortem diltiazem and desacetyl-diltiazem concentrations, measured by gas chromatography-mass spectrometry, were as follows: 31.1 mg/mL diltiazem and 9.7 mg/mL desacetyl-diltiazem in blood; 33.1 mg/g diltiazem and 13.7 mg/g desacetyl-diltiazem in brain; 179.5 mg/g diltiazem and 47.5 mg/g desacetyl-diltiazem in lung; 41.8 mg/g diltiazem and 10.1 mg/g desacetyl-diltiazem in heart; 182.1 mg/g diltiazem and 47.3 mg/g desacetyl-diltiazem in liver; 49.2 mg/g diltiazem and 22.6 mg/g desacetyl-diltiazem in kidney; and 294.9 mg/mL diltiazem and 29.4 mg/mL desacetyl-diltiazem in bile. It is interesting to note that although several cases of acute diltiazem poisoning have been reported in literature, only a few were lethal. Diltiazem concentrations found in our case are notably higher than those reported in other studies, including those in which diltiazem ingestion resulted in the death of the patient. Notably, in many of these latter cases, the doses of diltiazem ingested were higher than those taken by our patient.