Everything about Metoclopramide totally explained
Metoclopramide (
INN) (or /ˌmɛtəˈklɒprəmaɪd) is a potent
dopamine receptor antagonist used for its
antiemetic and
prokinetic properties. Thus it's 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.
Mode of action
Metoclopramide was first described by Dr. Louis Justin-Besançon and C. Laville in
1964. It appears to bind to
dopamine D2 receptors where it's 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. At higher doses, 5-HT
3 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-HT
4 receptor agonist activity. The prokinetic 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. 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.
In nausea and vomiting associated with cancer
chemotherapy, it has been superseded by the more effective
5-HT3 antagonists (for example
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 (for example 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 (for example 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.
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.
The risk of EPSEs are increased in young adults (<20 years) and children.
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.
[Further Information]
Get more info on 'Metoclopramide'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://metoclopramide.totallyexplained.com">Metoclopramide Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
