METOCLOPRAMIDE HYDROCHLORIDE

METOCLOPRAMIDE HYDROCHLORIDE (met-oh-kloe-pra'mide) Emex , Maxeran , Reglan Classifications: prokinetic agent (gi stimulant); Therapeutic: gi stimulant Pregnancy Category: B

Availability

5 mg, 10 mg tablets; 5 mg/5 mL solution; 5 mg/mL injection

Action

Potent central dopamine receptor antagonist. Increases resting tone of esophageal sphincter, and tone and amplitude of upper GI contractions. As a result, gastric emptying and intestinal transit are accelerated with little effect, if any, on gastric, biliary, or pancreatic secretions. Antiemetic action results from drug-induced elevation of CTZ threshold and enhanced gastric emptying.

Therapeutic Effect

Enhances GI motility and is an effective antinauseant. In diabetic gastroparesis, indicated by relief of anorexia, nausea, vomiting, persistent fullness after meals.

Uses

Management of diabetic gastric stasis (gastroparesis); to prevent nausea and vomiting associated with emetogenic cancer chemotherapy (e.g., cisplatin, dacarbazine) or surgery; to facilitate intubation of small bowel; symptomatic treatment of gastroesophageal reflux.

Contraindications

Sensitivity or intolerance to metoclopramide; allergy to sulfiting agents; history of seizure disorders; concurrent use of drugs that can cause extrapyramidal symptoms; pheochromocytoma; mechanical GI obstruction or perforation; ileus; history of breast cancer.

Cautious Use

CHF, cardiac disease; sulfite hypersensitivity, asthma, hypokalemia, hypertension; depression; hepatic disease, infertility, methemoglobin reductase deficiency, Parkinson's disease, kidney dysfunction; GI hemorrhage; G6PD deficiency, procainamide hypersensitivity, seizure disorder, seizures, tardive dyskinesia; history of intermittent porphyria; pregnancy (category B); lactation.

Route & Dosage

Gastroesophageal Reflux Adult: PO 10–15 mg q.i.d. a.c. and h.s. Child: PO 0.4–0.8 mg/kg/d in 4 divided doses Diabetic Gastroparesis Adult: PO/IV/IM 10 mg q.i.d. a.c. and h.s. for 2–8 wk Geriatric: PO 5 mg a.c and h.s. Small-Bowel Intubation, Radiologic Examination Adult: IM/IV 10 mg administered over 1–2 min Child: IM/IV <6 y, 0.1 mg/kg over 1–2 min; 6–14 y, 2.5–5 mg over 1–2 min Chemotherapy-Induced Emesis Adult: PO 20–40 mg q4–6h, may repeat IM/IV 2 mg/kg 30 min before antineoplastic administration, may repeat q2h for 2 doses, then q3h for 3 doses if needed Postoperative Nausea/Vomiting Adult: IM/IV 10–20 mg near end of surgery

Administration

Oral

• Give 30 min before meals and at bedtime.

Intravenous Note: Verify correct IV concentration and rate of infusion for administration to infants or children with physician. PREPARE: Direct: Doses of 10 mg or less may be given undiluted.  IV Infusion: Doses >10 mg IV should be diluted in at least 50 mL of D5W, NS, D5/.45% NaCl, RL or other compatible solution.   ADMINISTER: Direct: Give over 1–2 min (or longer in pediatric patients).  IV Infusion: Give over not less than 15 min.   INCOMPATIBILITIES Solution/additive: Calcium gluconate, chloramphenicol, cisplatin, dexamethasone, erythromycin, floxacillin, fluorouracil, furosemide, lorazepam, methotrexate, penicillin G potassium, sodium bicarbonate, tetracyclines. Y-site: Allopurinol, amphotericin B cholesteryl complex, amsacrine, cefepime, doxorubicin liposome, furosemide, propofol, TPN.

• Discard open ampules; do not store for future use.

• Store at 15°–30° C (59°–86° F) in light-resistant bottle. Tablets are stable for 3 y; solutions and injections, for 5 y.

Adverse Effects (≥1%)

CNS: Mild sedation, fatigue, restlessness, agitation, headache, insomnia, disorientation, extrapyramidal symptoms (acute dystonic type), neurologic malignant syndrome with injection. GI: Nausea, constipation, diarrhea, dry mouth, altered drug absorption. Skin: Urticarial or maculopapular rash. Body as a Whole: Glossal or periorbital edema. Hematologic: Methemoglobinemia. Endocrine: Galactorrhea, gynecomastia, amenorrhea, impotence. CV: Hypertensive crisis (rare).

Diagnostic Test Interference

Metoclopramide may interfere with gonadorelin test by increasing serum prolactin levels.

Interactions

Drug: Alcohol and other cns depressants add to sedation; anticholinergics, opiate analgesics may antagonize effect on GI motility; phenothiazines may potentiate extrapyramidal symptoms; may decrease absorption of acetaminophen, aspirin, atovaquone, diazepam, digoxin, lithium, tetracycline; may antagonize the effects of amantadine, bromocriptine, levodopa, pergolide, ropinirole, pramipexole; may cause increase in extrapyramidal and dystonic reactions with phenothiazines, thioxanthenes, droperidol, haloperidol, loxapine, metyrosine; may prolong neuromuscular blocking effects of succinylcholine.

Pharmacokinetics

Absorption: Readily from GI tract. Onset: 30–60 min PO; 10–15 min IM; 1–3 min IV. Peak: 1–2 h. Duration: 1–3 h. Distribution: to most body tissues including CNS; crosses placenta; distributed into breast milk. Metabolism: Minimally in liver. Elimination: 95% in urine, 5% in feces. Half-Life: 2.5–6 h.

Nursing Implications

Assessment & Drug Effects

• Report immediately the onset of restlessness, involuntary movements, facial grimacing, rigidity, or tremors. Extrapyramidal symptoms are most likely to occur in children, young adults, and the older adult and with high-dose treatment of vomiting associated with cancer chemotherapy. Symptoms can take months to regress.
• Be aware that during early treatment period, serum aldosterone may be elevated; after prolonged administration periods, it returns to pretreatment level.
• Lab tests: Periodic serum electrolytes.
• Monitor for possible hypernatremia and hypokalemia (see Appendix F), especially if patient has HF or cirrhosis.
• Adverse reactions associated with increased serum prolactin concentration (galactorrhea, menstrual disorders, gynecomastia) usually disappear within a few weeks or months after drug treatment is stopped.

Patient & Family Education

• Avoid driving and other potentially hazardous activities for a few hours after drug administration.
• Avoid alcohol and other CNS depressants.
• Report S&S of acute dystonia, such as trembling hands and facial grimacing (see Appendix F), immediately.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug