Palonosetron-induced anaphylaxis during general anesthesia in a patient with multiple drug hypersensitivity.

BACKGROUND: Palonosetron, a second-generation 5-HT3 receptor antagonist, is widely used for postoperative nausea and vomiting (PONV) prophylaxis. Anaphylaxis induced by palonosetron during general anesthesia is extremely rare, and the risk of severe anaphylaxis upon re-exposure in polysensitized atopic patients is inadequately recognized. CASE REPORT: A 50-year-old female underwent an uneventful hepatectomy, receiving palonosetron without adverse reaction. Ten weeks later, during pre-induction for laparoscopic rectal cancer surgery, she received oxycodone, palonosetron, and penehyclidine hydrochloride. One minute after completion, she developed generalized rash (> 60% body surface area), hypotension (81/50 mmHg), and tachycardia (125 bpm), requiring vasopressor support; surgery was cancelled. Subsequent skin testing was positive for ondansetron (++), cisatracurium (+), and propofol (+), while negative for chlorhexidine, rocuronium, and etomidate. CONCLUSION: Prior uneventful exposure to palonosetron does not guarantee future safety. Atopic patients with polysensitization are at significantly increased risk of severe anaphylaxis upon re-exposure. Positive ondansetron skin testing provides indirect evidence identifying palonosetron as the culprit. All 5-HT3 receptor antagonists should permanently be avoided in such patients, and alternative antiemetics (e.g., dexamethasone, droperidol, NK1 antagonists) should be selected.