METEX XR

What it is

METEX XR contains metformin hydrochloride. It is available in 500 mg, 750 mg and 1000 mg tablet strengths. Metformin is a biguanide with antihyperglycaemic effects, lowering both basal and postprandial plasma glucose. It does not stimulate insulin secretion and therefore does not cause hypoglycaemia.

Approved indications

— Type 2 diabetes mellitus in adults, children from 10 years of age and adolescents, particularly in overweight patients, when dietary management and exercise alone does not result in adequate glycaemic control. — In adult patients, metformin may be used as initial treatment or in sulfonylurea failures either alone or in combination with a sulfonylurea and other oral agents or as adjuvant therapy in insulin requiring type 2 diabetes.

Dosing overview

Tablets should be taken in divided doses with meals. Initially 500 mg should be taken once or twice a day and if necessary increased over a few weeks up to 1 g three times per day. The dose should be titrated with gradual dose increments until the desired effect is obtained. 500 mg three times a day is often sufficient to obtain diabetic control. If necessary, the dose can be increased to 1 g three times daily, which is the maximum recommended daily dose. In children from 10 years of age and adolescents, the usual starting dose is one tablet of 500 mg or 850 mg once daily, given during meals or after meals. The maximum recommended dose of metformin is 2 g daily, taken as two or three divided doses.

Key safety warnings

Life threatening lactic acidosis can occur due to accumulation of metformin. Risk factors include renal impairment, old age and the use of high doses of metformin above 2 g per day. Lactic acidosis is a rare but serious metabolic complication that can occur due to metformin accumulation. Reported cases have occurred primarily in diabetic patients with significant renal failure. The risk of lactic acidosis must be considered in the event of non-specific signs such as muscle cramps with digestive disorders such as abdominal pain and severe asthenia. Lactic acidosis is characterised by acidotic dyspnea, abdominal pain and hypothermia followed by coma. Metformin induces a reduction in thyrotropin (thyroid stimulating hormone (TSH)) levels in patients with treated or untreated hypothyroidism. Regular monitoring of TSH levels is recommended in patients with hypothyroidism. It is recommended that vitamin B12 serum levels are monitored annually. The risk of low vitamin B12 levels increases with increasing metformin dose, treatment duration, and/or in patients with risk factors known to cause vitamin B12 deficiency.

Contraindications

Contraindications include juvenile diabetes mellitus that is uncomplicated and well regulated on insulin; diabetes mellitus regulated by diet alone; any type of metabolic acidosis (such as lactic acidosis, diabetic ketoacidosis); hypersensitivity to metformin hydrochloride or to any of the excipients; renal failure or renal dysfunction (creatinine clearance < 60 mL/min); acute conditions with the potential to alter renal function such as dehydration, severe infection and shock; acute or chronic disease which may cause tissue hypoxia such as cardiac failure, recent myocardial infarction, respiratory failure, pulmonary embolism and shock; severe hepatic insufficiency; acute alcohol intoxication and alcoholism. Metformin must also be avoided during or immediately following elective major surgery.

Regulatory history

METEX XR metformin hydrochloride 500 mg and 1000 mg modified release tablets were first listed on the ARTG on 2015-09-10, with a 750 mg strength also registered. Additional bottle pack presentations were listed on 2025-06-26.