This MedLibrary.org supplementary page on Metoclopramide is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
 |
|
 |
|
|
Metoclopramide
|
|
| Systematic (IUPAC) name | |
| 4-amino-5-chloro-N-(2-(diethylamino)ethyl)- 2-methoxybenzamide |
|
| Identifiers | |
| CAS number | |
| ATC code | A03 |
| PubChem | |
| DrugBank | |
| Chemical data | |
| Formula | C14H22ClN3O2 |
| Mol. mass | 299.80 g/mol |
| Pharmacokinetic data | |
| Bioavailability | 80±15% (oral) |
| Metabolism | Hepatic |
| Half life | 5–6 hours |
| Excretion | 70–85% renal, 2% faecal |
| Therapeutic considerations | |
| Pregnancy cat. | |
| Legal status |
S3/S4 (Au), POM (UK), ℞-only (U.S.) |
| Routes | Oral, IV, IM |
Metoclopramide (INN) (pronounced /ˌmɛtəˈkloʊprəmaɪd/ or /ˌmɛtəˈklɒprəmaɪd) is a potent dopamine receptor antagonist used for its antiemetic and prokinetic properties. Thus it is primarily used to treat nausea and vomiting, and to facilitate gastric emptying in patients with gastroparesis.
It is available under various trade names including: Maxolon (Shire/Valeant), Reglan (Wyeth), Degan (Lek), Maxeran (Sanofi Aventis), Primperan (Sanofi Aventis), and Pylomid (Bosnalijek). It was protected under U.S. patent (3177252) until 6 April 1982.
Contents |
Mode of action
Metoclopramide was first described by Dr. Louis Justin-Besançon and C. Laville in 1964.[1] It appears to bind to dopamine D2 receptors where it is a receptor antagonist, and is also a mixed 5-HT3 receptor antagonist/5-HT4 receptor agonist.
The anti-emetic action of metoclopramide is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone (CTZ) in the central nervous system (CNS)—this action prevents nausea and vomiting triggered by most stimuli.[2] At higher doses, 5-HT3 antagonist activity may also contribute to the anti-emetic effect.
The prokinetic activity of metoclopramide is mediated by muscarinic activity, D2 receptor antagonist activity and 5-HT4 receptor agonist activity.[3][4] The prokinetic effect itself may also contribute to the anti-emetic effect.
Clinical use
Antiemetic use
Metoclopramide is commonly used to treat nausea and vomiting (emesis) associated with conditions including: emetogenic drugs, uraemia, radiation sickness, malignancy, labor, and infection.[5][6] It is also used by itself or in combination with paracetamol (acetaminophen) (paracetamol/metoclopramide available in UK as Paramax) or aspirin (MigraMax) for the relief of migraine.
It is considered ineffective in postoperative nausea and vomiting (PONV) at standard doses, and ineffective for motion sickness.[5][6] In nausea and vomiting associated with cancer chemotherapy, it has been superseded by the more effective 5-HT3 antagonists (e.g. ondansetron).
Prokinetic use
Metoclopramide increases peristalsis of the jejunum and duodenum, increases tone and amplitude of gastric contractions, and relaxes the pyloric sphincter and duodenal bulb. These prokinetic effects make metoclopramide useful in the treatment of gastric stasis (e.g. after gastric surgery or diabetic gastroparesis), as an aid in gastrointestinal radiology by increasing transit in barium studies, and as an aid in difficult small intestinal intubation. It is also used in gastroesophageal reflux disease (GERD/GORD).
Other indications
By inhibiting the action of prolactin inhibiting hormone (i.e. dopamine), metoclopramide has sometimes been used to stimulate lactation.
Contraindications/precautions
Metoclopramide is contraindicated in phaeochromocytoma. It should be used with caution in Parkinson's disease since, as a dopamine antagonist, it may worsen symptoms. Long-term use should be avoided in patients with clinical depression as it may worsen mental state.[6] Also contraindicated with a suspected bowel obstruction.
Adverse effects
Common adverse drug reactions (ADRs) associated with metoclopramide therapy include: restlessness, drowsiness, dizziness, lassitude, and/or dystonic reactions. Infrequent ADRs include: headache, extrapyramidal effects (EPSE) such as oculogyric crisis, hypertension, hypotension, hyperprolactinaemia leading to galactorrhoea, diarrhoea, constipation, and/or depression. Rare but serious ADRs associated with metoclopramide therapy include: agranulocytosis, supraventricular tachycardia, hyperaldosteronism, neuroleptic malignant syndrome and/or tardive dyskinesia.[6]
The risk of EPSEs are increased in young adults (<20 years) and children.[6] Such dystonic reactions are usually treated with benztropine or procyclidine. The risk of tardive dyskinesia and EPSE is increased with high dose therapy and with prolonged use. Tardive dyskinesias may be persistent and irreversible in some patients.[5]
Wikipedia content modification information:
- This page was last modified on 13 July 2008, at 02:44.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Metoclopramide".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.