Granisetron is a serotonin 5-HT₃ receptor antagonist used as an antiemetic to treat

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

and vomiting following

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemother ...

and radiotherapy. Its main effect is to reduce the activity of the

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

, which is a nerve that activates the vomiting center in the

medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (invol ...

. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or

muscarinic receptor Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-rec ...

s. 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. Sancuso is manufactured by 3M Drug Delivery Systems for Kyowa Kirin, Inc. It was patented in 1985 and approved for medical use in 1991. It is on the World Health Organization's List of Essential Medicines.

Medical uses

Chemotherapy

It may be used for

-induced nausea and vomiting and appears to work about the same as ondansetron. The most common side-effects of chemotherapy treatment are nausea, vomiting and diarrhea. This is one type of drug that a doctor can prescribe to prevent, lessen, or relieve discomfort.

Post operative

A number of medications including granisetron appear to be effective in controlling

post-operative nausea and vomiting Postoperative nausea and vomiting (PONV) is the phenomenon of nausea, vomiting, or retching experienced by a patient in the postanesthesia care unit (PACU) or within 24 hours following a surgical procedure. PONV affects about 10% of the population ...

(PONV). It is unclear if it is more or less effective than other agents such as droperidol, metoclopramide, or ondansetron.

Gastroparesis

The granisetron patch (Sancuso) has been studied for use in gastroparesis, though it is not FDA approved for this indication.

Other

* Is a possible therapy for nausea and vomiting due to acute or chronic medical illness or acute gastroenteritis * Treatment of cyclic vomiting syndrome although there are no formal trials to confirm efficacy.

Adverse effects

Granisetron is a well-tolerated drug with few side effects. Headache, dizziness, and constipation are the most commonly reported side effects associated with its use. There have been no significant drug interactions reported with this drug's use. It is broken down by the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...

cytochrome P450 Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various co ...

system and it has little effect on the metabolism of other drugs broken down by this system.

Extended release

An extended release injectable version of granisetron, known as Sustol is also available in the United States as of 2016. The long acting form is used for the treatment of both acute and delayed CINV in moderately emetogenic chemotherapy and anthrocycline and/or cyclophosphamide (AC) highly emetogenic regimens. In its review, the FDA did not grant the broad HEC label to the drug citing the focus on AC regimens, primarily breast-cancer, and lack of data.FDA.go
Sustol Prescribing Information