Blamed but not at fault: anti-obesity medication adverse effects misidentified as perioperative complications - a comprehensive review and medicolegal warning for anesthesiologists.

The rapid proliferation of anti-obesity medications (AOMs), including glucagon-like peptide-1 receptor agonists (GLP-1 RAs), the dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 agonist tirzepatide, and non-incretin agents, including orlistat, phentermine, and bupropion/naltrexone, has created an underappreciated perioperative patient safety hazard. Existing guidelines have focused narrowly on GLP-1 RAs and aspiration risk, leaving some critical gaps unaddressed: (1) the misidentification trap, whereby drug-induced adverse effects, including acute pancreatitis, bowel obstruction, sudden visual loss, and neuropsychiatric dysfunction, are clinically and radiographically indistinguishable from surgical or anesthetic complications, exposing clinicians to unwarranted blame, and (2) the full perioperative risk profile of non-GLP-1 AOM classes. This narrative review synthesizes the current pharmacovigilance evidence, consensus guidelines, and clinical case data to address these gaps. Non-arteritic anterior ischemic optic neuropathy (NAION) from semaglutide (hazard ratio [HR] = 7.64; World Health Organization safety alert 2025) may be attributed to anesthetic corneal injury, emotional lability may be misinterpreted as emergence delirium, drug-induced pancreatitis from GLP-1 RAs (adjusted HR = 9.09 vs. comparator) may be misattributed to the operating surgeon, and bowel obstruction from premature postoperative GLP-1 RA resumption has prompted unnecessary re-laparotomy. Structured preoperative AOM documentation, explicit postoperative hold orders, and the inclusion of drug etiology in postoperative differentials constitute the defensible standard of care in the era of pharmacological obesity management.