REGLAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for REGLAN (REGLAN).
Metoclopramide is a dopamine D2 receptor antagonist and a serotonin 5-HT4 receptor agonist. It enhances gastrointestinal motility by increasing acetylcholine release from myenteric nerve terminals and sensitizes tissues to acetylcholine. It also has central antiemetic effects via chemoreceptor trigger zone blockade.
| Metabolism | Metabolized via hepatic CYP2D6, CYP1A2, and CYP3A4; main metabolite is monodeethylmetoclopramide; also undergoes sulfation and glucuronidation. |
| Excretion | Approximately 85% of an oral dose is excreted in urine (as unchanged drug and conjugates) and about 5-10% in feces via biliary elimination. |
| Half-life | Terminal elimination half-life is 4 to 6 hours in patients with normal renal function. In patients with creatinine clearance <40 mL/min, half-life is prolonged significantly, requiring dose adjustment. |
| Protein binding | Approximately 30% bound to plasma proteins (mainly albumin). |
| Volume of Distribution | 2 to 3 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral: 75% (first-pass metabolism reduces absolute bioavailability to about 75%); Intramuscular: 80-100%. |
| Onset of Action | Oral: 30 to 60 minutes; Intravenous: 1 to 3 minutes; Intramuscular: 10 to 15 minutes. |
| Duration of Action | Oral: 1 to 2 hours; Intravenous: 1 to 2 hours; Intramuscular: 1 to 2 hours. Duration may be prolonged in renal impairment. |
| Action Class | Dopamine (D2) receptor antagonist-Prokinetic agent |
| Brand Substitutes | Reggi 10mg Tablet, Dysvon 10mg Tablet, Vominorm 10mg Tablet, Emenorm 10mg Tablet, Metvo 10mg Tablet, Metromide 10mg Injection, Metotid 5mg Syrup, Zerinorm 5mg Syrup, Metocan 5mg Syrup, Maxeron 5mg Syrup, Clomet Syrup, Esmet 5mg Injection, Almet 5mg Injection, Vominorm 5mg Injection, Clomet 5mg Injection, Johnlee Metoclopramide Injection |
10 mg orally 4 times daily 30 minutes before meals and at bedtime; or 5-10 mg intramuscularly or intravenously every 4-6 hours as needed; maximum 30 mg/day intravenous for diabetic gastroparesis.
| Dosage form | INJECTABLE |
| Renal impairment | GFR 10-50 mL/min: reduce dose by 25-50%; GFR <10 mL/min: reduce dose by 75%. |
| Liver impairment | No specific guidelines; use caution in severe hepatic impairment (Child-Pugh C) as clearance may be reduced. |
| Pediatric use | 0.1-0.2 mg/kg/dose orally or intravenously 4 times daily; maximum single dose 10 mg; not recommended for neonates. |
| Geriatric use | Initiate at 5 mg orally 4 times daily; risk of tardive dyskinesia and sedation increased; use lowest effective dose; monitor for extrapyramidal symptoms. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for REGLAN (REGLAN).
| Breastfeeding | Metoclopramide (REGLAN) is excreted into human breast milk with a milk-to-plasma ratio of approximately 1.8. At standard maternal doses, infant exposure is low (~5-10% of maternal weight-adjusted dose). American Academy of Pediatrics considers it compatible with breastfeeding, but monitor infant for gastrointestinal effects or extrapyramidal symptoms. |
| Teratogenic Risk | First trimester: No evidence of major malformations in human studies, but caution is advised due to dopamine antagonist effects. Second and third trimesters: Chronic use may cause extrapyramidal signs in neonates, including tardive dyskinesia, withdrawal symptoms, or neuroleptic malignant syndrome. Late third trimester: Risk of neonatal hypoglycemia if mother used near term. |
■ FDA Black Box Warning
Tardive dyskinesia (TD) can occur with chronic or high-dose use, especially in elderly patients, particularly elderly women. Risk increases with duration of treatment and cumulative dose. Therapy should be discontinued if signs or symptoms of TD develop. Avoid use for longer than 12 weeks except in rare cases where benefit outweighs risk.
| Serious Effects |
["Hypersensitivity to metoclopramide or any component","History of tardive dyskinesia from metoclopramide or other antipsychotics","Gastrointestinal hemorrhage, mechanical obstruction, or perforation","Pheochromocytoma (risk of hypertensive crisis)","Concurrent use of MAOIs within 14 days","Epilepsy or seizure disorder (may increase seizure frequency)","Parkinson's disease (worsens symptoms)"]
| Precautions | ["Tardive dyskinesia risk with chronic use; limit to <12 weeks unless life-threatening","Neuroleptic malignant syndrome (NMS)","Parkinsonian symptoms, akathisia, restlessness","Depression and increased suicide risk","Hypertension in patients with pheochromocytoma","Prolactin elevation; monitor for galactorrhea, gynecomastia, menstrual irregularities","Avoid in patients with gastrointestinal hemorrhage, obstruction, or perforation","May precipitate a hypertensive crisis in patients with MAOI use; avoid concomitant use"] |
Loading safety data…
| Fetal Monitoring | Maternal: monitor for extrapyramidal symptoms, tardive dyskinesia, neuroleptic malignant syndrome, and gastrointestinal motility changes. Fetal/neonatal: if used near term, monitor for extrapyramidal signs, hypoglycemia, and withdrawal symptoms. Consider periodic liver function tests if long-term therapy. |
| Fertility Effects | Metoclopramide elevates prolactin levels, which may cause galactorrhea, amenorrhea, and anovulation, potentially impairing fertility. Effects are reversible upon discontinuation. |