Neurological disorders
Extrapyramidal disorders may occur, particularly in children and young adults, and/or when high doses are used. These reactions usually occur at the beginning of the treatment and can occur after a single administration. Metoclopramide should be discontinued immediately in the event of extrapyramidal symptoms. These effects are generally completely reversible after treatment discontinuation, but may require a symptomatic treatment (benzodiazepines in children and/or anticholinergic anti-Parkinsonian medicinal products in adults).
The time interval of at least 6 hours specified in section 4.2 should be respected between each metoclopramide administration, even in case of vomiting of the dose, in order to avoid overdose.
Prolonged treatment with metoclopramide may cause tardive dyskinesia, which is potentially irreversible, especially in the elderly. Treatment should not exceed 3 months because of the risk of tardive dyskinesia (see section 4.8). Treatment must be discontinued if clinical signs of tardive dyskinesia appear.
Neuroleptic malignant syndrome has been reported with metoclopramide in combination with neuroleptics as well as with metoclopramide monotherapy (see section 4.8). Metoclopramide should be discontinued immediately in the event of symptoms of neuroleptic malignant syndrome and appropriate treatment should be initiated.
Special care should be exercised in patients with underlying neurological conditions and in patients being treated with other drugs that act on the central nervous system (see section 4.3).
Symptoms of Parkinson's disease may also be exacerbated by metoclopramide.
Methaemoglobinaemia
Methaemoglobinaemia which could be related to NADH cytochrome b5 reductase deficiency has been reported. In such cases, metoclopramide should be immediately and permanently discontinued and appropriate measures initiated (such as treatment with methylene blue).
Cardiac disorders
There have been reports of serious cardiovascular undesirable effects including cases of circulatory collapse, severe bradycardia, cardiac arrest and QT prolongation following administration of metoclopramide by injection, particularly via the intravenous route (see section 4.2 and 4.8).
Special care should be taken when administering metoclopramide, particularly via the intravenous route to the elderly population, to patients with cardiac conduction disorders (including QT prolongation), patients with uncorrected electrolyte imbalance, bradycardia and those taking other drugs known to prolong QT interval (such as class IA and III antiarrhythmics, tricyclic antidepressants, macrolides, antipsychotics (see section 4.8)).
Intravenous doses should be administered as a slow bolus (over at least 3 minutes) in order to reduce the risk of adverse effects (e.g. hypotension, akathisia).
Renal and hepatic impairment
In patients with renal impairment or with severe hepatic impairment, a dose reduction is recommended (see section 4.2).
Other precautions
Metoclopramide may cause elevation of serum prolactin levels.
Care should be exercised when using metoclopramide in patients with a history of atopy (including asthma) or porphyria.
Special care should be taken when administering metoclopramide intravenously to patients with “sick sinus syndrome” or other cardiac conduction disturbances.
This medicinal product contains less than 1 mmol sodium (= 23 mg) per dose, that is to say essentially 'sodium- free'.