Metoclopramide
Class: Antiemetic Agents; Prokinetic Agents
Pharmacology
Mechanism of Action
Blocks dopamine receptors in chemoreceptor trigger zone of CNS and sensitizes tissues to acetylcholine; increases upper GI motility but not secretions; increases lower esophageal sphincter tone .Absorption
Bioavailability: IM, 74-96%; PO, 65-95%Onset: IV, 1-3 min; IM, 10-15 min; PO, 30-60 min
Duration: 1-2 hr regardless of route
Peak plasma time: IV, 15 min; PO, 60-120 min
Distribution
Protein bound: 30-40%Vd: 3.5 L/kg
Metabolism
Metabolized by liverMetabolites: Metoclopramide glucuronides, metoclopramide sulfates, aminoacetic acid (inactive)
Elimination
Half-life: IV/IM, 4-5 hrDialyzable: Not significant; dose adjustment after dialysis unnecessary
Total body clearance: 0.53-0.55 L/hr/kg (prolonged in neonates as compared with adults)
Excretion: Primarily urine (85%
Dosing & Uses
Adult
Dosing Forms & Strengths
injectable solution :5mg/mL
syrup :5mg/5mL
tablet :5mg ,10mg
Chemotherapy-Induced Nausea & Vomiting
2 mg/kg IV (infused over at least 15 minutes) 30 minutes before chemotherapy, then repeated 2 more times q2hr (after initial dose)Vomiting suppressed: Decrease to 1 mg/kg IV q3hr for 3 doses
Vomiting not suppressed: Continue same dose q3hr for 3 doses
Diabetic Gastroparesis
10 mg IV/IM/PO q6hr 30 minutes before meals and at bedtime; use injectable dosing only if severe symptoms are presentSmall Bowel Intubation/Radiologic Examination of Upper GI Tract
10 mg IV over 1-2 minutesGastroesophageal Reflux Disease
10-15 mg PO q6hr 30 minutes before meals and at bedtime; not to exceed 80 mg/dayPostoperative Nausea & Vomiting (Off-label)
10-20 mg IM administered near end of procedure; may be repeated postoperatively q4-6hr PRNPediatric
Small Bowel Intubation/Radiologic Examination of Upper GI Tract
6-14 years old: 2.5-5 mg IV over 1-2 minutes
>14 years old: 10 mg IV over 1-2 minutes
Gastroesophageal Reflux Disease (Off-label)
Neonate: 0.15 mg/kg IV q6hrInfant: 0.1 mg/kg IV/IM/PO q6-8hr 30 minutes before meals and at bedtime
Not to exceed 0.3-0.75 mg/kg/day
Diabetic Gastroparesis (Off-label)
>6 years old: 0.5 mg/kg/day PO divided q8hr
Postoperative Nausea & Vomiting (Off-label)
0.1-2 mg/kg IV q6-8hr PRNContraindications & Cautions
Black Box Warnings
May cause tardive dyskinesia (often irreversible)Risk of developing tardive dyskinesia increases with treatment duration and total cumulative dose
Discontinue with signs or symptoms of tardive dyskinesia
No known treatment exists for tardive dyskinesia
Symptoms may lessen or resolve after metoclopramide treatment is stopped
Do not administer for longer than 12 weeks, except in rare cases where therapeutic benefit is thought to outweigh risk of tardive dyskinesia
Contraindications
Hypersensitivity to metoclopramide or procainamideGI hemorrhage, mechanical obstruction, perforation, epilepsy, pheochromocytoma
Other drugs causing extrapyramidal symptoms (eg, phenothiazines, butyrophenones)
Cautions
Mental depression, parkinsonismSuture lines after GI anastomosis or closure
Hypertension, CHF
Renal impairment, cirrhosis
Can cause tardive dyskinesia (see Black Box Warnings), especially in elderly; discontinue if signs or symptoms of tardive dyskinesia develop (metoclopramide itself may completely or partially suppress these manifestations); tardive dyskinesia may persist even after drug is discontinued
Diphenhydramine 50 mg IM can be given for extrapyramidal symptoms
Pregnancy & Lactation
Pregnancy category: B
Lactation: Drug crosses into breast milk; use caution; concern may be warranted according to American Academy of Pediatrics
Adverse Effects
10%
Extrapyramidal symptoms (dystonic reactions in 25% of young adults 18-30 years old)1-10%
Fatigue (10%)Restlessness (10%)
Sedation (10%)
Frequency Not Defined
DiarrheaNausea
Galactorrhea
Gynecomastia
Impotence
Menstrual disorders
Neuroleptic malignant syndrome
Hematologic abnormalities
SOURCE : metoclopramide
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