A first look at duloxetine (Cymbalta) in a postmortem laboratory

Area of Science:

• Forensic Toxicology
• Analytical Chemistry
• Pharmacology

Background:

• Duloxetine (Cymbalta) is a serotonin and norepinephrine reuptake inhibitor approved by the FDA for depression and neuropathic pain.
• New drug approvals present challenges for toxicology labs regarding detection and interpretation.
• The Los Angeles County Department of Coroner Toxicology Laboratory has developed methods for duloxetine analysis.

Observation:

• Duloxetine was detected and quantified in 12 postmortem cases using gas chromatography-mass spectrometry (GC-MS).
• A basic, liquid-liquid extraction with n-butylchloride was employed for sample preparation.
• The analytical method demonstrated linearity from 0.05 to 3.0 mg/L with a limit of detection at 0.03 mg/L.

Findings:

• Postmortem duloxetine concentrations varied across biological matrices: central blood (ND-0.59 mg/L), femoral blood (ND-0.26 mg/L), vitreous humor (ND-0.23 mg/L), liver (0.28-22 mg/kg), gastric contents (0.08-86 mg), bile (0.57-3.1 mg/L), and urine (0.07-0.47 mg/L).
• This study represents the first reported detection and quantification of duloxetine in postmortem casework.

Implications:

• Provides essential reference data for forensic toxicologists analyzing duloxetine in postmortem investigations.
• Aids in the interpretation of duloxetine concentrations in relation to cause and manner of death.
• Contributes to the understanding of duloxetine's postmortem distribution and stability.