A fatal intoxication due to doxepin.

Area of Science:

• Forensic Toxicology
• Pharmacology

Background:

• Tricyclic antidepressants (TCAs) like doxepin are commonly prescribed but can be fatal in overdose.
• Accurate quantification of drug and metabolite levels in biological matrices is crucial for forensic investigations.

Observation:

• A fatal intoxication case involving doxepin was investigated.
• Doxepin and its primary metabolite, desmethyldoxepin, were quantified in blood, urine, and various tissues.
• Analytical methods included thin-layer chromatography (TLC) and gas chromatography with flame-ionization detection (GC/FID).
• The technique allowed for the isomeric differentiation of doxepin (cis and trans).

Findings:

• Significant concentrations of doxepin and desmethyldoxepin were detected in multiple tissues.
• A notably high ratio of doxepin to desmethyldoxepin was observed specifically in myocardial (heart) tissue.
• The analytical method proved effective for quantitative analysis and isomer determination.

Implications:

• The findings highlight the importance of tissue analysis in fatal intoxication cases.
• The unusual myocardial doxepin:desmethyldoxepin ratio may offer insights into drug distribution and metabolism in critical overdose scenarios.
• This case underscores the utility of advanced chromatographic techniques in forensic toxicology.