Domperidone.
Posted by JP on 13 February, 2008
Domperidone (trade name Motilium or Motillium) is an antidopaminergic drug, developed by Janssen Pharmaceutica, and used orally to suppress paediatric Gastroesophageal reflux (infant vomiting).
Domperidone works primarily by blocking dopamine receptors found in an area of the brain known as the chemoreceptor trigger zone (CTZ). The CTZ is activated by nerve messages from the stomach when an irritant is present. It is also activated directly by agents circulating in the blood, for example anti-cancer medicines. Once activated, it sends messages to another area of the brain, the vomiting centre, which in turn sends messages to the gut, causing the vomiting reflex.
Blocking the dopamine receptors in the CTZ prevents nausea messages from being sent to the vomiting centre. This reduces the sensation of nausea and prevents vomiting.
Domperidone also blocks dopamine receptors found in the upper end of the digestive system. This results in tightening of the muscles at the entry to the stomach, relaxation of the muscles at the exit of the stomach and increased contraction of the muscles in the stomach itself. These actions speed the passage of food through the stomach into the intestine, which physically helps to prevent vomiting.
This medicine is not recommended for long term use.
Janssen Pharmaceutical has brought Domperidone before the FDA several times in the last two decades, with the most recent effort in the 1990s. Numerous U.S. clinical drug trials have demonstrated its safety and efficacy in dealing with gastroparesis symptoms, but the FDA turned down Janssen’s application for Domperidone, even though the FDA’s division of gastrointestinal drugs had approved Domperidone.
There is a new controversy in Britain regarding lethal levels of sodium found in children who are administered this drug. It is now subject to a medical review following a number of criminal trials.
