Trimethobenzamide (trade names Tebamide, Tigan) is an

antiemetic An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may ...

used to prevent

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 the ...

and

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the Human nose, nose. Vomiting can be the result of ailments like Food-poisoning, foo ...

Mechanism of action

Trimethobenzamide is an

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

of the D₂ receptor. It is believed to affect the

chemoreceptor trigger zone The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting. The CTZ is located within the area ...

(CTZ) of 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 (involun ...

to suppress

and

Side effects

Possible side effects include drowsiness, dizziness, headache, muscle cramps, and blurred vision. More serious adverse effects include skin rash, tremors,

parkinsonism Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), rigidity, and postural instability. These are the four motor symptoms found in Parkinson's disease (PD), after which it is named, dementia with Lewy bo ...

, and

jaundice Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme meta ...

Formulations

Trimethobenzamide is marketed under the brand names Tebamide and Tigan, manufactured by

GlaxoSmithKline GSK plc, formerly GlaxoSmithKline plc, is a British multinational pharmaceutical and biotechnology company with global headquarters in London, England. Established in 2000 by a merger of Glaxo Wellcome and SmithKline Beecham. GSK is the ten ...

and

King Pharmaceuticals King Pharmaceuticals, is a pharmaceutical company, a wholly owned subsidiary of Pfizer based in Bristol, Tennessee. Before being acquired by Pfizer, it was the world's 39th largest pharmaceutical company. On October 12, 2010, King was acquired by ...

, respectively. It is available as oral capsules and injectable formulations. Trimethobenzamide was also available as a rectal

suppository A suppository is a dosage form used to deliver medications by insertion into a body orifice where it dissolves or melts to exert local or systemic effects. There are three types of suppositories, each to insert into a different sections: rectal su ...

, but such formulations were banned by the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

on April 6, 2007, due to unproven efficacy.

Synthesis

Alkylation of the sodium salt of ''p''-hydroxybenzaldehyde (1) with 2-dimethylaminoethyl chloride affords the ether (2). Reductive amination of the aldehyde in the presence of ammonia gives diamine (3). Acylation of that product with 3,4,5-trimethoxybenzoyl chloride affords trimethobenzamide (4).

References

External links

Tebamide

Tigan
(manufacturer's website) {{Dopaminergics Antiemetics Benzamides D2 antagonists Phenol ethers