Antiemetics · Gastrointestinal
Metoclopramide
Maxeran® · Reglan®(brand names vary by market)
An antiemetic that moves the stomach, and can lock up the neck.
Also: oral liquid, injection
Mechanism
Central and peripheral D2 antagonism plus 5-HT4 agonism: it blocks the chemoreceptor trigger zone and accelerates gastric emptying at the same time.
Indications
- Nausea and vomiting, especially with gastric stasis
- Diabetic gastroparesis
- Migraine, both for nausea and to aid absorption of analgesia
- Facilitating small bowel intubation
Formulations
Dosing concepts
Duration limit
Restricted to short courses, typically no more than five days in many jurisdictions, because tardive dyskinesia risk rises with cumulative exposure.
Age
Extrapyramidal reactions are commonest in the young and in older adults, at opposite ends of the age range and for different reasons.
Concepts, not prescribing instructions. Practice numbers live in current references and local protocols.
Pharmacokinetics
- Bioavailability
- ~80%
- Half-life
- 5 to 6 h, longer in renal impairment
- Elimination
- renal: Substantially renal; dose reduced as clearance falls
- Protein binding
- ~30%
Adverse effects
- Acute dystonic reactionseriousOculogyric crisis, torticollis, trismus, typically within hours of a dose and dramatic. Treated with an anticholinergic and resolves in minutes.
- AkathisiacommonDistressing inner restlessness, easily mistaken for anxiety.
- Tardive dyskinesiaseriousCumulative-exposure related and may be irreversible: the reason for the duration limit.
- Drowsinesscommon
- Hyperprolactinemiacommon
Contraindications & precautions
Contraindications
- Gastrointestinal obstruction, perforation or haemorrhage
- Phaeochromocytoma
- Parkinson disease
- History of tardive dyskinesia
Precautions
- Young adults and adolescents
- Older adults
- Renal impairment
- Concurrent antipsychotics
Interactions
No curated interaction entries yet for this agent.
Monitoring
Movement effects
Acute dystonia within hours, akathisia within days, tardive dyskinesia over months
Duration of use
The exposure limit is the safety mechanism
Renal function
It sets the dose
Counselling points
- Tell us immediately about muscle spasms, a stiff neck, or eyes rolling upward. This is treatable within minutes.
- Restlessness or an inability to sit still is a side effect, not anxiety.
- This is a short-term medicine.
Clinical pearls
- An acute dystonic reaction in a young woman after a dose in the emergency department is the classic presentation, and it is frightening to everyone until the diagnosis is made. It reverses within minutes with an anticholinergic.
- Its prokinetic action makes it the right antiemetic for gastroparesis and the wrong one for obstruction, where increasing propulsion against a blockage is harmful.
References & review
- Metoclopramide product monograph (consult the current version for your market) (monograph)
- Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed. (reference-work)
Last reviewed 2026-08-16 · jurisdiction: global · drug information changes; verify against current references before practice use.