Dopaminergic blocking agents – GI emptying ( delayed) adjunct ; Peristaltic stimulant : It is believed that metoclopramide inhibits gastric smooth muscle relaxation produced by dopamine , thus enhancing cholinergic responses of the GI smooth muscle . It accelerates intestinal transit and gastric emptying by preventing relaxation of gastric body and increasing the phasic activity of antrum . At the same time , this action is accompanied by relaxation of the upper small intestine , resulting in an improved coordination between the body and antrum of the stomach and the upper small intestine . It decreases reflux into the esophagus by increasing the resting pressure of the lower esophageal sphincter and improves acid clearance from the esophagus by increasing amplitude of esophageal contractions.
Antiemetic – Dopamine antagonist action raises the threshold of activity in the chemoreceptor trigger zone and decreases the input from afferent visceral nerves .
Metoclopramide stimulates prolaction secretion and causes a transient increase in circulation aldosterone levels, which may be associated with transient fluid retention.

Gastroparesis (treatment ) – Metoclopramide is indicated for the relief of symptoms of acute and recurrent diabetic gastroparesis .
Gastroesophageal reflux (treatment) – Oral metoclopramide is indicated in adults for the symptomatic short- term treatment of heartburn and reflux esophagitis due to delayed gastric emptying . In infants , it is used in the treatment of chronic vomiting and recurrent bronchopulmonary manifestations associated with gastroesophageal reflux.
Metoclopramide is used for correcting the slow gastric emptying in postvagotomy stasis , in idiopathic stasis , and in various collagen diseases such as scleroderma . In addition , it is used for persistent functional feeding intolerance and gastric stasis in preterm infants.

a- Those indicating need for medical attention : Agranulocytosis ; Cardiovascular effects , specifically hypotension ; Hypertension ; Tachycardia ; Dystonic extrapyramidal effects ; Parkinsonian extrapyramidal effects; Tardive dyskinesia With high doses – Agitation ; Panic- like sensation ; Restless legs syndrome
b- Those indicating need for medical attention only if they continue or are bothersome: Diarrhea (with high doses ) ; Drowsiness ; Restlessness ; Unusual tiredness or weakness ; Breast tenderness and swelling ; Changes in menstruation ; Constipation ; Dizziness ; Headache; Insomnia ; Mental depression ; Prolactin stimulation ; Nausea ; Skin rash ; Unusual dryness of mouth ; Unusual irritability

Hypersensitivity to metoclopramide or any component of the formulation ; GI mechanical obstruction , perforation or hemorrhage ; Pheochromocytoma ; Epilepsy

Use with caution in patients with Parkinson’s disease and in patients with a history of mental depression . The frequency of extrapyramidal symptoms is higher in pediatric patients and adults < 30 years of age ; risk is increased at higher dosages . Use caution with concurrent use of other drugs associated with EPS. Metoclopramide may cause transient increase in serum aldosterone ; use with caution in patients who are at risk of fluid overload (CHF , cirrhosis) . Use with caution in patients with hypertension or following surgical anastomosis / closure . Patients with NADH- cytochrome b5 reductase deficiency are at increased risk of methemoglobinemia and / or sulfhemoglobinemia . Abrupt discontinuation may (rarely) result in withdrawal symptoms (dizziness, headache , nervousness ) . Risk of extrapyramidal effects may be increased in severe , chronic renal failure ; reduced dosage is recommended. Administration in asthmatic patients may increase risk of bronchospasm.

Concurrent use with alcohol may increase the CNS depressant effects of either alcohol or metoclopramide ; concurrent use also may accelerate gastric emptying of alcohol , thus possibly increasing its rate and extent of absorption from the small intestine . Concurret use with anticholinergics and opioid – containing medications may antagonize the effects of metoclopramide on GI motility . Prior administration of metoclopramide may decrease the emetic response to apomorphine ; also , concurrent use may potentiate the CNS depressant effects of either apomorphine or metoclopramide . Metoclopramide may increase serum prolactin concentration and interfere with effects of bromocriptine; dosage adjustment of bromocriptine may be necessary . Concurrent use with cimetidine may decrease the effect of cimetidine due to decreased absorption . Concurrent use with CNS depression – producing medications may increase the sedative effects of either these medications or metoclopramide . The decrease in gastric emptying time caused by metoclopramide may increase the bioavilability of cyclosporine ; monitoring of its concentration may be necessary . Concurrent use may decrease absorption of digoxin from stomach ; dosage adjustment of digoxin may be necessary . Metoclopramide has been reported to decrease the effectiveness of levodopa with concurrent use . Concurrent use with metoclopramide may accelerate absorption of mexiletine . Metoclopramide should be used cautiously in patients receiving MAO inhibitors, including furazolidine and procarbazine.

Periodic renal function test ; monitor for signs of hypoglycemia in patients using insulin and those being treated for gastroparesis