Information last reviewed: May 2026 — for educational purposes only.
Reglan (metoclopramide) is a prescription dopamine D2 receptor antagonist with prokinetic (gastric motility-enhancing) properties. It has two main mechanisms: (1) central D2 blockade in the chemoreceptor trigger zone (CTZ), which provides antiemetic activity; and (2) peripheral enhancement of upper GI motility by blocking the inhibitory dopaminergic control of gastric smooth muscle, which accelerates gastric emptying, raises lower oesophageal sphincter tone, and increases antral contractions. This dual action makes it unique among antiemetics — it is the only commonly used agent that both reduces nausea centrally and physically speeds gastric emptying peripherally, making it the drug of choice for gastroparesis.
Metoclopramide is indicated for: diabetic gastroparesis (delayed gastric emptying in diabetic patients causing nausea, vomiting, and early satiety); idiopathic gastroparesis; short-term (≤12 weeks) treatment of symptomatic GERD; and prevention of chemotherapy-induced nausea and vomiting (though 5-HT3 antagonists are now preferred for CINV). It is also used in hospital settings for post-operative nausea, small bowel intubation facilitation, and as an adjunct to GI procedures.
What Is Metoclopramide?
Metoclopramide (brand: Reglan, Metozolv ODT) is both a D2 antagonist and a weak 5-HT4 receptor agonist in the gut — the latter contributing to its prokinetic effects. Unlike traditional antiemetics (prochlorperazine, promethazine), metoclopramide's primary clinical niche is gastroparesis, where it reduces vomiting and nausea by actually accelerating the gastric emptying that is delayed. It crosses the blood-brain barrier, leading to both its central antiemetic effects and its central side effects including EPS, sedation, and — most seriously — tardive dyskinesia.
Prescription Status and Black Box Warning
Metoclopramide is prescription-only in the United States. The FDA has issued a black box warning (the most serious warning category) against use of metoclopramide for more than 12 consecutive weeks due to the risk of developing tardive dyskinesia (TD) — a potentially irreversible movement disorder characterised by involuntary, repetitive movements of the face, tongue, lips, and extremities. Risk of TD increases with duration of use and cumulative dose. Treatment should be stopped immediately if signs of TD appear.
Strengths and Available Forms
- 5 mg tablets — taken 30 minutes before meals and at bedtime; standard starting dose; useful for dose titration
- 10 mg tablets — most common effective adult dose; prescribed 4 times daily (30 min before each of 3 meals + at bedtime) for gastroparesis
- 10 mg orally disintegrating tablets (ODT — Metozolv) — dissolves on tongue without water; useful for patients with nausea who struggle to swallow
- 5 mg/5 mL oral syrup — for paediatric use and for adults unable to swallow tablets; same dosing schedule
- 5 mg/mL injection (IV/IM) — used in hospital for acute gastroparesis exacerbation, PONV, diabetic gastroparesis flares, and chemotherapy antiemesis; IV: slow push over 15 minutes to reduce risk of akathisia
- Nasal spray (Gimoti) 15 mg — approved 2020; nasal spray for adult women with acute diabetic gastroparesis; first non-oral, non-injectable form; avoids GI absorption issues
Maximum recommended oral dose for gastroparesis is 40 mg/day (10 mg QID). Duration should not exceed 12 weeks. Reduce dose in renal impairment.
Price of Reglan / Generic Metoclopramide
Generic metoclopramide tablets are available at very low cost at US pharmacies and are often on the $4 generic list at major pharmacy chains. Brand-name Reglan costs more. The nasal spray Gimoti is significantly more expensive. Insurance coverage for the ODT and nasal spray varies.
Frequently Asked Questions
What is tardive dyskinesia and why is the 12-week limit so important?
Tardive dyskinesia (TD) is an involuntary movement disorder caused by chronic dopamine D2 blockade — particularly in the nigrostriatal pathway. It manifests as repetitive lip smacking, tongue thrusting, facial grimacing, and sometimes limb or trunk movements. It occurs in a proportion of patients on long-term metoclopramide and — crucially — can be irreversible even after stopping the drug. The 12-week limit in the black box warning exists because risk increases substantially beyond this period. Short-course use (days to a few weeks) for acute nausea is generally safe; it is the chronic daily use in gastroparesis that demands the time limit and regular risk reassessment.
Why is metoclopramide specifically used for gastroparesis when other antiemetics are not?
Most antiemetics (ondansetron, promethazine, prochlorperazine) reduce the sensation of nausea centrally but do not address the underlying delay in gastric emptying that causes nausea in gastroparesis. Metoclopramide's prokinetic D2/5-HT4 mechanism actually accelerates gastric emptying — treating the root cause (delayed emptying) and the symptom (nausea) simultaneously. This makes it uniquely suited to gastroparesis. Domperidone (not FDA-approved) is a peripheral-only D2 antagonist used in other countries for this indication with fewer central side effects.
Can metoclopramide cause restlessness or anxiety shortly after a dose?
Yes — akathisia (a feeling of inner motor restlessness, an irresistible need to move) is a common and distressing side effect, particularly with IV administration if given too quickly. It can be mistaken for anxiety or agitation. Slowing the IV infusion rate minimises this. Oral akathisia may also occur and can be treated with low-dose benzodiazepines or diphenhydramine if severe. Any abnormal movements should be reported to the prescribing physician promptly.
Disclaimer: This page is for general informational purposes only and does not constitute medical advice. Always consult a licensed healthcare professional before taking any medication. See our full disclaimer.