Definition: Mallophagan is a medication used to treat nausea and vomiting caused by certain types of chemotherapy, including cisplatin. It works by blocking the action of acetylcholinesterase, which is responsible for the release of acetylcholine, a neurotransmitter that helps to reduce nausea and vomiting. This can help to alleviate symptoms associated with chemotherapy-induced nausea and vomiting.