A suspected case of serotonin syndrome induced by palonosetron and ramosetron administration

Abstract

Serotonin syndrome occurs when serotonin (5-hydroxytryptamine, 5-HT) levels increase and is accompanied by symptoms of mental status chang-es, neuromuscular abnormalities, and autonomic hyperactivity. Sero-tonin receptor 3 antagonists, such as palonosetron or ramosetron, are commonly used for their antiemetic effects during general anesthesia. However, overdosage of these drugs carries a risk of serotonergic tox-icity as they increase serum serotonin levels due to inhibition of sero-tonin reuptake. Serotonin syndrome caused by 5-HT₃ antagonists is thought to be caused by the synergistic effects of high doses of seroto-nergic drugs or the combination of two or more serotonergic drugs with different mechanisms of action. The incidence of serotonin syndrome is unknown because it is a rare condition that cannot be selected for in randomized clinical trials. Therefore, physicians must focus on the clini-cal manifestations of the syndrome and manage patients before the condition becomes life-threatening.