Dopaminergic blocking agents - Exact mechanism of action is unkown, however, it is believed that inhibits gastric smooth muscle relaxation produced by dopamine, thus enhancing cholinergic responses of the gastrointestinal smooth muscle. Accelerates intestinal transit and gastric emptying by preventing relaxation of gastric body and increasing the phasic activity of antrum. This action is accompained 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. 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 peristaltic contractions.
Antiemetic - Dopamine antagonist action raises the threshold of activity in the chemoreceptor trigger zone and decreases the input from afferent visceral nerves. Other actions / effects: Stimulates prolactin secretion and causes a transient increase in circulating aldosterone levels.

Oral metoclopramide is indicated in adults for the symptomatic short -term treatment of heartburn and reflux esophagitis due to delayed gastric emptying. It is indicated for the relief of symptoms of acute and recurrent diabetic gastroparesis.
ln preterm infants, it is used for persistent functional feeding intolerance and gastric stasis.

Risk - benefit should be considered when the following medical problems exist: Asthma - Liver failure - Parkinson's disease - Renal failure, severe, chronic (reduced dosage is recommended) - Sensitivity to metoclopramide, procaine, or procainamide.
Contraindications are: Epilepsy; Gastrointestinal hemorrhage, mechanical obstruction, or perforation; Pheochromocytoma.

Extensive studies in humans have not been done. Studies in animals have not shown that metoclopramide causes adverse effects in the fetus.
Problems in humans have not been documented; however, risk benefit must be considered since metoclopramide is distributed into breast milk.

Combinations containing any of the following medications, depending on the amount present, may also interact with this medication:
Alcohol, Medications with anticholinergic activity, Opioid - containing medications, Apomorphine, Bromocriptine, Cimetidine, CNS - depressants, Cyclosporine, Digoxin, Extrapyramidal reaction - causing medications, Hepatotoxic medications, Levodopa and Monoamine oxidase (MAO) inhibitors including furazolidine and procarbazine.

Those indicating need for medical attention. Incidence rare: Agranulocytosis; cardiovascular effects (specifically hypotension); tachycardia; extrapyramidal effects, parkinsonian; tardive dyskinesia.

Usual adult and adolescent dose: Treatment of diabetic gastroparesis -10 mg 30 minutes before symptoms are likely to occur or before each meal and at bedtime, up to four times a day. Treatment of gastroesophageal reflux - 10 to 15 mg 30 minutes before symptoms are likely to occur or before each meal and at bedtime, up to four times a day.
Usual adult and adolescent prescribing limits are up to 0.5 mg per kg of body weight per day.
Usual pediatric dose: 0.1 to 0.2 mg per kg of body weight per dose, given 30 minutes before meals and at bedtime. Children 5 to 14 years of, age: 2.5 to 5 mg three times a day 30 minutes before meals and at bedtime.