METACLOPROMIDE

General Information

Preparation Strength

 Inj Metaclopromide 10mg /2ml

Description

A widely used antiemetic and prokinetic agent.

Mode of Action

         Acts by sensitizing GI smooth muscle to acetylcholine, as well as an inherent      cholinomimetic property. Hence, it increses peristaltic activity, increases lower esophageal sphincter tone, increases gastric motility and decreases emptying time, relaxes the pyloric sphincter. The antiemetic properties of metaclopromide are due to dopamine receptor antagonist properties and hence blocks stimulation of CT2 in medulla by dopamine.

Pharmacokinetics

* After IV administration, onset of action is 1-3 minutes and after IM 10-15 minutes. Plasma half life is 5-6 hours. Excreted in urine as both unchanged drug and metabolites.

Clinical Information

Indication

Antiemetic action :

* Prevention of nausea, vomiting during postoperatives, with cancer chemotherapy, drug induced, due to migraines, radiation therapy.

Gastro kinetic agent :

* Stasis due to diabetic gastro paresis, post surgical, post vagatomy.

* For radiological examination - emergency barium meal series.

* For gastro esophageal reflux disease.

* For facilitation of small bowel intubation (it relaxes the pyloric sphincter).

* For prevention of aspiration in emergency G.A procedures.

Dosage

* For nausea - 10 mg IM / IV.

* If used for cancer chemotherapy higher antiemetic action is required - 2 mg / kg.

Routes of Administration

* Oral, IM, IV, Rectally.

Contraindications

* Whenever stimulation of GI motility is dangerous - haemorrhage, perforation, obstruction of GIT.

* In Phaeochromocytoma, since it may precipitate hypertensive crisis due to catecholamine release .
* In epileptics / patients with extrapyramidal diseases of CNS.
Precautions / Practice points
* With caution in hypertensive patients especially when given IV - hypertensive crisis occur due to endogenous catecholamine release.
* Patients to be instructed not to drive / operate machinery as it causes sedation and drowsiness.
* Lactation to be avoided as it is excreted in breast milk.
* If renal impairment (creatinine clearence < 40 ml / minute) half the dose to be administered.
* Do not mix with cephalosporine, chloram phenicol, sodium bicarbonate - chemical incompatibility.

Drug Interactions
* CNS depressants like alcohol, sedative hypnotics, narcotics may increase sedative effects.
* Anti-muscaranic agents and opioid analgesics antagonise the actions of metaclopramide.
* When given with patients on MAO inhibitors, hypertensive crisis may occur due to release of endogenous catacholamine.
* Decrease absorption of digoxin.
* Increases absorption of acetaminophen, L-Dopa, alcohol, tetracyclines.

Adverse effects
CNS
* Drowsiness, fatigue, lassitude. Mental depression with suicidal tendency, confusion, disorientation may also occur.
* Extrapyramidal symptoms - acute dystonic reactions, involuntary limb movements, oculogyric crisis, grimacing, tongue protusion, trismus, laryngospasm and depth may occur. Treatment - 50 mg of diphenhydramin or 1-2 mg IM of benztropine.
* Tardive dyskinesia, and parkinsonism may occur when used for longer period of time.

Endocrine
* Hyperprolactinemia due to dopamine receptors antagonism causes galactorrhea, amenorrhea, gynoecomastia.

Rare effects :

CVS
* Hypertension, tachyarrythmias (on IV administration)
* Hepatotoxicity on chronic use.
* Allergic reactions - rashes, urticaria.

Drug Toxicity
* Drowsiness, disorientation, extrapyramidal reactions, methenoglobinemia in infants.

Treatment of Toxicity
* Anticholinergics, diphenhydramine for extrapyramidal reactions.

Storage
* Store in airtight containers protected from light.

Shelf life
* 3 years.