| Blood and lymphatic system disorders Very rare cases of red cell disorders such as methaemoglobinaemia (which could be related to NADH cytochrome b5 reductase deficiency particularly in neonates) and sulphaemoglobinaemia have been reported, particularly at high doses of metoclopramide, and may be more severe in patients with G6PD deficiency. Metoclopramide should be withdrawn and appropriate treatment instituted.Immune system disorders Very rarely, hypersensitivity, including anaphylaxis, bronchospasm and cutaneous reactions, has been reported (see also Skin and subcutaneous tissue disorders)Endocrine disorders Raised prolactin levels, resulting in galactorrhoea, irregular menstrual periods and gynaecomastia may occur during metoclopramide therapy.Psychiatric disorders Rare cases of confusion, restlessness, anxiety and depression have been reported.Nervous system disorders Metoclopramide may cause extrapyramidal reactions such as acute dystonia and dyskinesia, parkinsonian syndrome, akathisia, even following administration of a single dose of the drug, particularly in children and young adults (see Section 4.4.). These reactions may occur following single or low dose regimes, but are more likely if the dose of metoclopramide is above 500 micrograms per kg body weight. Dystonic reactions include: spasm of the facial muscles, trismus, rhythmic protrusion of the tongue, a bulbar type of speech, spasm of the extra-ocular muscles including oculogyric crises, unnatural positioning of the head and shoulders and opisthotonos. Extrapyramidal reactions generally occur within 24 48 hours of starting treatment, and the effects usually disappear within 24 hours of withdrawal of the drug.Should treatment of a dystonic reaction be required, an anticholinergic anti-Parkinson drug, or a benzodiazepine may be used.Chronic tardive dyskinesia, which may be irreversible, has developed in patients receiving long term therapy with metoclopramide. This occurs most commonly in geriatric patients (particularly women) and usually develops following discontinuation of the drug. It is manifested by orobuccolingual dyskinetic movements. Patients on prolonged therapy should be regularly reviewed. Very rare occurrences of neuroleptic malignant syndrome have been reported. This syndrome is potentially fatal and comprises hyperpyrexia, altered consciousness, muscle rigidity, autonomic instability and elevated levels of creatine phosphokinase (CPK) and must be treated urgently (recognised treatments include dantrolene and bromocriptine). Metoclopramide should be stopped immediately if this syndrome occurs.Drowsiness, fatigue and dizziness may occur (rare).Cardiac disorders Very rare reports of abnormalities of cardiac conduction (bradycardia, asystole, heart block) have been reported following intravenous administration.Vascular disorders Transient hypotension followed by compensatory tachycardia may occur.Hypertensive crises have occurred in patients with phaeochromocytomas given metoclopramide.Gastrointestinal disorders DiarrhoeaSkin and subcutaneous tissue disorders Skin reactions such as rash, pruritus, angioedema and urticaria.General and Administration Site Disorders Very rare reports of injection site inflammation and local phlebitis have been received | |