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What is Granisetron and explain in detail?
Granisetron is a serotonin 5-HT3 receptor antagonist used as an antiemetic to treat nausea and vomiting following chemotherapy and radiotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata.  It does not have much effect on vomiting due to motion sickness.  This drug does not have any effect on dopamine receptors or muscarinic receptors.
Granisetron was developed by chemists working at the British drug company Beecham around 1985 and is available as a generic. It is produced by Roche Laboratories under the trade name Kytril. The drug was approved in the United Kingdom in 1991 and in United States in 1994 by the FDA.
A granisetron transdermal patch with the trade name Sancuso was approved by the US FDA on September 12, 2008