-5%
Paloxiron is indicated for:
- Acute nausea and vomiting
- Chemotherapy-induced nausea and vomiting (CINV):
- Acute CINV: Occurs on the day of chemotherapy treatment.
- Delayed CINV: Occurs on days following chemotherapy.
- Radiotherapy-induced nausea and vomiting (RINV)
- Post-operative and post-discharge nausea and vomiting (PONV & PDNV)
Palonosetron is a 5-HT3 receptor antagonist with a high affinity for the receptor. Chemotherapy triggers the release of serotonin from enterochromaffin cells in the small intestine, activating 5-HT3 receptors in the vagus nerve and the brain’s chemoreceptor trigger zone, which leads to nausea and vomiting. Palonosetron blocks serotonin at 5-HT3 receptors, preventing this emetic response. It acts both in the small intestine and the brain.
Palonosetron demonstrates linear pharmacokinetics over 1-90 mcg/kg. After IV administration, 40% is excreted unchanged in urine within 144 hours. It has a volume of distribution of 6.9–7.9 L/kg, with about 62% plasma protein binding. Approximately 50% is metabolized into inactive metabolites via renal pathways and CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP2E1, and CYP3A4/5). Its half-life is approximately 40 hours, indicating prolonged receptor binding.