Effects of Bariatric Surgery Observed in Postmortem Toxicology Casework

Bariatric surgery has been on the rise and patients often have multiple indications for pre- and post-operative pharmacotherapy. Procedures target the stomach and/or small intestine and affect weight loss through restriction, malabsorption, or a combination of the two. The absorption and/or metabolism of drugs via the gastrointestinal tract could be altered by different mechanisms. Several cases at the North Carolina Office of the Chief Medical Examiner's Toxicology Laboratory (NCOCME) have raised questions about the potential impact of these procedures on the disposition of drugs in the body and how that altered disposition may affect cause and manner of death. Overmedication and postmortem redistribution are not enough to explain the phenomena seen in some NCOCME bariatric surgery-related casework. Case examples include a 46-year-old female with a history of Roux-en-Y gastric bypass (RYGB) who suffered a witnessed collapse. Toxicological findings included elevated concentrations of oxymorphone at 0.49 mg/L in vena cava blood. A 67-year-old female, who died from vomiting and bacterial gastritis one day after placement of two intragastric weight-loss balloons, had elevated concentrations of duloxetine at 1.4 mg/L in the iliac vein blood and 9.3 mg/kg in the liver. Her medication was strictly controlled by her sister and gastric contents were without intact tablets or residue at autopsy.