(Other name for: palonosetron hydrochloride) OR A drug used to prevent nausea and vomiting caused by chemotherapy. It is also used to prevent nausea and vomiting after surgery. Aloxi blocks the action of the chemical serotonin in the brain, which may help lessen nausea and vomiting. It is a type of serotonin receptor antagonist and a type of antiemetic. Also called palonosetron hydrochloride.