Metvex

Each mL contains: Metoclopramide (as Hydrochloride) 5 mg.

Pharmacology: Pharmacokinetics: Metoclopramide is rapidly and almost completely absorbed from the gastrointestinal tract following a dose by mouth, although conditions such as vomiting or impaired gastric motility may reduce absorption. However, it undergoes hepatic first pass metabolism, which varies considerably between subjects, and hence absolute bioavailability and plasma concentrations are subject to wide inter individual variation. On average, the bioavailability of oral metoclopramide is about 75%, but it varies between about 30 to 100%. Peak plasma concentrations of metoclopramide occur about 1 to 2 hours after an oral dose. Bioavailability is equally variable following rectal or intranasal administration, although it may be somewhat better if the drug is given intramuscularly.
Metoclopramide is widely distributed in the body with an apparent volume of distribution of about 3.5 liters per kg. It readily crosses the blood-brain barrier into the CNS. It also freely crosses the placenta, and has been reported to attain concentrations in fetal plasma about 60 to 70% of those in maternal plasma. Concentrations higher than those in maternal plasma may be reached in the breast milk of lactating mothers, particularly in the early puerperium, although concentrations decrease somewhat in the late puerperium. Elimination of metoclopramide is biphasic, with a terminal elimination half-life of about 4 to 6 hours although this may be prolonged in renal impairment, with consequent elevation of plasma concentrations. It is excreted in the urine, about 85% of a dose being eliminated in 72 hours, 20 to 30% unchanged metoclopramide and the remainder as sulfate or glucuronide conjugates, or as metabolites. About 5% of a dose is excreted in faeces via the bile.

Metoclopramide is used in disorders of decreased gastrointestinal motility such as gastroparesis or ileus; in gastro-oesophageal reflux disease and dyspepsia; and in nausea and vomiting associated with various gastrointestinal disorders, with migraine, following surgery, and with cancer therapy. Metoclopramide is of no value in the prevention or treatment of motion sickness. It may be used to stimulate gastric emptying during radiographic examinations, to facilitate intubation of the small bowel, and in the management of aspiration syndromes.

Metoclopramide is usually given as the hydrochloride monohydrate with doses expressed as the anhydrous hydrochloride. The recommended dose by mouth, intramuscularly, or by slow intravenous injection, is 10 mg (expressed as anhydrous metoclopramide hydrochloride) three times daily. Single doses should be considered where appropriate and single doses of 10 mg to 20 mg (expressed as anhydrous base or anhydrous hydrochloride) have been used. The use of metoclopramide is restricted in patients under 20 years of age to severe intractable vomiting of known cause, chemotherapy- or radiotherapy-induced vomiting, as an aid to gastrointestinal intubation, and in premedication. Suggested doses for those aged 15 to 19 years and weighing 60 kg and over are 10 mg three times daily; 5 mg three times daily for patients 15 to 19 years old and weighing 30 to 59 kg; 9 to14 years (30 kg and over), 5 mg three times daily; 5 to 9 years (20 to 29 kg), 2.5 mg three times daily; 3 to 5 years (15 to 19 kg), 2 mg two or three times daily; 1 to 3 years (10 to 14 kg), 1 mg two to three times daily; and under 1 year (up to 10 kg) 1 mg twice daily. Where body-weight is below that specified for a given age group, the dose should reflect the weight rather than the age, so that a lower dose is chosen or as prescribed by the physician.
High dose therapy. High doses of metoclopramide have been used in the treatment of the nausea and vomiting associated with cancer chemotherapy often in combination with other agents such as dexamethasone. The loading dose of metoclopramide given before cancer therapy is 2 to 4 mg per body-weight administered as a continuous intravenous infusion over 15 to 20 minutes and is followed by a maintenance dose of 3 to 5 mg per kg, again as a continuous intravenous infusion, administered over 8 to 12 hours. Alternatively, initial doses up to 2 mg per kg by intravenous infusion over at least 15 minutes may be given before cancer therapy and repeated every 2 or 3 hours. The total dosage by either continuous or intermittent infusion should not normally exceed 10 mg per kg in 24 hours.

Metoclopramide should not be used when stimulation of muscular contractions might adversely affect gastrointestinal haemorrhage, obstruction, perforation, or immediately after surgery. There have been reports of hypertensive crises in patients with phaeochromocytoma given metoclopramide, thus its use is not recommended in such patients. Children, young patients, and the elderly should be treated with care as they are at increased risk of extrapyramidal reactions. Patients in prolonged therapy should be reviewed regularly. Care should also be taken when metoclopramide is administered to patients with renal impairment, epilepsy, Parkinson's disease, or a history of depression. Metoclopramide may cause drowsiness or impaired reactions; patients so affected should not drive or operate machinery.

Metoclopramide is a dopamine antagonist and may extrapyramidal symptoms which usually occur as acute dystonic reactions; these are more common in children and young adults, especially if female, and at daily doses above 500 μg per kg body-weight. Parkinsonism and tardive dyskinesia have occasionally occurred, usually during prolonged treatment in elderly patients. Other adverse effects include restlessness, drowsiness, and diarrhea. Hypotension, dizziness, headache, and depression may occur and there are isolated reports of blood disorders, hypersensitivity reactions, and neuroleptic malignant syndrome. Disorders of cardiac conduction have been reported with intravenous metoclopramide. Metoclopramide stimulates prolactin secretion and may cause galactorrhoea or related disorders. Transient increases in plasma-aldosterone concentrations have been reported.

Caution should be observed when using metoclopramide in patients taking other drugs that can also cause extrapyramidal reactions, such as the phenothiazines. Increased toxicity may occur if metoclopramide is used in patients receiving lithium, and in caution is advisable with other centrally active drugs such as antiepileptics. Antimuscarinics and opioid analgesics antagonise the gastrointestinal effects of metoclopramide. The absorption of other drugs may be affected by metoclopramide; it may either diminish absorption from the stomach (as with digoxin) or enhance absorption from the small intestine. It inhibits serum cholinesterase and may prolong neuromuscular blockade produced by suxamethonium and mivacurium. Metoclopramide may also increase prolactin blood concentrations and therefore interfere with drugs which may have a hypoprolactinaemic effect such as bromocriptine. It has been suggested that it should not be given to patients receiving MAIOs.

Store at temperatures not exceeding 30°C. Protect from light.

Antiemetics / GIT Regulators, Antiflatulents & Anti-Inflammatories

A03FA01 - metoclopramide ; Belongs to the class of propulsives. Used in the treatment of functional gastrointestinal disorders.

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