Semaglutide and health risk: Development and validation of a LC-HRMS method for testing semaglutide in whole blood and application to real cases.

The use of semaglutide, also known by its trade name Ozempic®, has been increasing worldwide in recent years due to its benefits in treating type II diabetes. Thanks to its effects on appetite regulation, in many countries it is also used to treat obesity. However, due to its promotion by social media and celebrities as a weight-loss treatment, semaglutide is misused by a non-diabetic and non-obese population and by a young public, which is the main target of these media. Following the alert by the ANSM (Agence nationale de sécurité du médicament) in France and the FDA (Food and Drug Administration) in the United States, which imposed the addition of fatal effects to the list of side effects, the misuse of semaglutide seems to be becoming a public health problem. For this reason, it seems important that a toxicology laboratory has the capacity to test for semaglutide in blood. In this study, the authors have developed and validated a method for the identification and quantification of semaglutide in whole blood using a LC-HRMS. After the addition of the internal standard (bovine insulin), the blood was subjected to protein precipitation using a mix of acetonitrile/methanol (70:30,v:v). The validation procedure demonstrated an acceptable linearity between 2 and 500 ng/mL. LOD and LOQ were 1 and 2 ng/mL, respectively. Intra and inter-day precision were below 20 % at three concentrations. The method was successfully applied to the blood samples of 3 diabetic patients under treatment of semaglutide. The samples tested positive with concentrations ranging from 31 to 70 ng/mL which fall within the limits of therapeutic blood concentrations described in the literature.

Bariatric surgery and changes in metformin distribution: About a fatal case.

A 65 year-old woman, suffering from mellitus type 2 diabetes and obesity, died at home, three days after bariatric surgery (Roux-en-Y gastric by-pass: RYGB). Her treatment, including metformin and dapagliflozin, was stopped before surgery and not postoperatively reinstalled. A forensic autopsy, toxicological and histological analyses were performed. No macroscopic or microscopic evidence of digestive perforation or peritonitis was identified, excluding an early surgery complication as the cause of death. Toxicological analysis revealed the presence of Metformin in all matrices tested, with a potentially fatal blood concentration. Death was attributed to lactic acidosis caused by a metformin overdose. With no evidence for suicide by ingestion of metformin, the authors supposed that the bariatric surgery might have caused changes in the absorption of metformin, leading to a rapid overdose and death. The only study in the literature on this subject, demonstrated a significant increase in the bioavailability of metformin following oral administration in gastric bypass patients. Thus, it can be anticipated that a therapeutic dose can become toxic when administrated to a subject who recently modified her digestive equipment. As this represents the first case of metformin overdose following bariatric surgery, further cases will be needed to confirm our initial observations.