metoclopramide hydrochloride
Apo-Metoclop ◆, Clopra, Maxeran ◆, Maxolon, Octamide, Reclomide, Reglan

Available forms
Available by prescription only
Injection: 5 mg/ml
Solution: 5 mg/5 ml, 10 mg/ml
Tablets: 5 mg, 10 mg

Indications and dosages
 Prevention or reduction of nausea and vomiting induced by highly emetogenic chemotherapy. Adults: 2 mg/kg I.V. given initially 30 minutes before highly emetogenic chemotherapy, followed by two additional doses of 2 mg/kg I.V. given q 2 hours. If emesis isn’t controlled, doses of 2 mg/kg I.V. may be repeated every 3 hours for three additional doses. If emesis is suppressed following the initial three doses, reduce dose to 1 mg/kg I.V. for three additional doses given at 3-hour intervals. Some clinicians have used up to 2.75 mg/kg by I.V. infusion to control nausea and vomiting ◇. Diphenhydramine 50 mg I.M. may be needed to control extrapyramidal symptoms at this dose. Less emetogenic chemotherapy requires initial doses of 1 mg/kg I.V. every 2 hours for three doses, then 1 mg/kg every 3 hours for three additional doses.
 Facilitation of small-bowel intubation and to aid in radiologic examinations. Adults and children older than age 14: 10 mg I.V. as a single dose over 1 to 2 minutes.
Children ages 6 to 14: 2.5 to 5 mg I.V. over 1 to 2 minutes.
Children younger than age 6: 0.1 mg/kg I.V. over 1 to 2 minutes.
 Delayed gastric emptying secondary to diabetic gastroparesis. Adults: 10 mg P.O. 30 minutes before meals and h.s. for 2 to 8 weeks, depending on response. Or, 10 mg I.M. or I.V. 30 minutes before meals and h.s. over 2 minutes. Therapy should be reinstituted at the earliest recurrence of symptoms.
 Gastroesophageal reflux. Adults: 10 to 15 mg P.O. q.i.d., taken 30 minutes before meals and h.s. for up to 12 weeks. Geriatric patients may need only 5 mg per dose.
 Postoperative nausea and vomiting. Adults: 10 to 20 mg I.M. near end of surgical procedure, repeated q 4 to 6 hours, p.r.n.
≡ Dosage adjustment. If creatinine clearance is less than 40 ml/minute, initial doses should be 50% of usual recommended doses and adjusted as tolerated.

Pharmacodynamics
Antiemetic action: Metoclopramide inhibits dopamine receptors in the chemoreceptor trigger zone of the brain to inhibit or reduce nausea and vomiting.
GI stimulant action: Drug relieves esophageal reflux by increasing lower esophageal sphincter tone and reduces gastric stasis by stimulating motility of the upper GI tract, thus reducing gastric emptying time.

Pharmacokinetics
Absorption: After oral administration, drug is absorbed rapidly and thoroughly from the GI tract. After I.M. administration, about 74% to 96% of drug is bioavailable.
Distribution: Distributed to most body tissues and fluids, including the brain. Drug crosses the placental barrier and is distributed in breast milk.
Metabolism: Not metabolized extensively; a small amount is metabolized in the liver via conjugation.
Excretion: Mostly excreted in urine and feces. Hemodialysis and renal dialysis remove minimal amounts.

Contraindications and precautions
Contraindicated in patients for whom stimulation of GI motility might be dangerous (such as those with hemorrhage, mechanical obstruction, or perforation), in patients hypersensitive to drug, and in those with pheochromocytoma or seizure disorders. Use cautiously in patients with history of depression, Parkinson’s disease, or hypertension.

Interactions
Drug-drug. Acetaminophen, aspirin, diazepam, levodopa, lithium, tetracycline: Increases absorption of these drugs. Monitor patient carefully.
Anticholinergics, opiates: May antagonize effect of metoclopramide on GI motility. Avoid use together if possible.
Antihypertensives, CNS depressants (such as sedatives and tricyclic antidepressants): May lead to increased CNS depression. Monitor patient carefully.
Butyrophenone antipsychotics, phenothiazine: May potentiate extrapyramidal reactions. Avoid use together if possible.
Cyclosporine: Increases absorption, possibly increasing its immunosuppressive and toxic effects. Monitor patient carefully.
Digoxin: Decreases absorption. Monitor serum digoxin levels.
MAO inhibitors: Increases blood pressure. Use together cautiously.
Drug-lifestyle. Alcohol use: May lead to increased CNS depression. Discourage alcohol use.

Adverse reactions
CNS: restlessness, anxiety, drowsiness, fatigue, lassitude, depression, akathisia, insomnia, confusion, suicidal ideation, seizures, hallucinations, headache, dizziness, extrapyramidal symptoms, tardive dyskinesia, fever, dystonic reactions.
CV: transient hypertension, hypotension, supraventricular tachycardia, bradycardia.
GI: nausea, bowel disturbances, diarrhea.
GU: urinary frequency, incontinence, prolactin secretion.
Respiratory: bronchospasm.
Skin: rash, urticaria.
Other: porphyria, loss of libido.

Effects on lab test results
• May increase aldosterone and prolactin levels.
• May decrease neutrophil and granulocyte counts.

Overdose and treatment
Effects of overdose include drowsiness, disorientation, dystonia, seizures, and extrapyramidal effects.
 Treatment includes symptomatic and supportive care, administration of antimuscarinics, antiparkinsonians, or antihistamines with antimuscarinic activity (such as 50 mg diphenhydramine, given I.M.).

Special considerations
• Drug has been used investigationally to promote postpartum lactation and treat anorexia nervosa, dizziness, migraine, and intractable hiccups. Oral form is being used investigationally to treat nausea and vomiting.
• Don’t use drug for longer than 12 weeks.
• Drug may be used to facilitate nasoduodenal tube placement.
• When oral concentrate is used, dilute with water, juice, or carbonated beverage or mix with semisolid food.
• Diphenhydramine may be used to counteract extrapyramidal effects of high-dose metoclopramide.
• For I.V. push, use undiluted and inject over a 1-to 2-minute period. For I.V. infusion, dilute with 50 ml of D₅W, dextrose 5% in half-normal saline injection, Ringer’s injection, or lactated Ringer’s injection, and infuse over at least 15 minutes. Solution is stable for 48 hours when stored at 39° to 86° F (4° to 30° C) and protected from light or for 24 hours when exposed to normal light. Drug may be added to total or partial parenteral nutrition.
• Drug is incompatible with cisplatin, methotrexate, cephalosporins, chloramphenicol, and sodium bicarbonate. Consult specific references for compatibility information.
• Administer by I.V. infusion 30 minutes before chemotherapy.
• Metoclopramide is photosensitive and will degrade when exposed to light. Protect all forms from light. Store at 59° to 86° F (15° to 30° C).
Breast-feeding patients
• Drug appears in breast milk. Use cautiously in breast-feeding women.
Pediatric patients
• Children have an increased risk of adverse CNS effects.
Geriatric patients
• Use drug cautiously, especially if patient has impaired renal function; dosage may need to be decreased.
• Geriatric patients are more likely to experience extrapyramidal symptoms and tardive dyskinesia.

Patient education
• Warn patient to avoid driving for 2 hours after each dose because drug may cause drowsiness.
• Until extent of CNS effect is known, advise patient not to consume alcohol.
• Tell patient to report twitching or involuntary movement.
• Instruct patient to take medication 30 minutes before each meal.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use