Diaxemet XR

What it is

DIAXEMET XR contains metformin hydrochloride. 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, DIAXEMET XR 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

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. Tablets should be taken in divided doses with meals. In children from 10 years of age and adolescents, metformin can be used as monotherapy. 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 of lactic acidosis in patients on metformin have occurred primarily in diabetic patients with significant renal failure. If metabolic acidosis is suspected, metformin should be discontinued, and the patient should be hospitalised immediately. 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. Gastrointestinal disorders such as diarrhoea, nausea, vomiting, abdominal pain and loss of appetite are very common. These undesirable effects occur most frequently during initiation of therapy and resolve spontaneously in most cases. To prevent them, it is recommended that metformin be taken in 2 or 3 daily doses during or after meals.

Contraindications

DIAXEMET XR is contraindicated in juvenile diabetes mellitus that is uncomplicated and well regulated on insulin; diabetes mellitus regulated by diet alone; during or immediately following surgery where insulin is essential; any type of metabolic acidosis (such as lactic acidosis, diabetic ketoacidosis); hypersensitivity to metformin hydrochloride or to any of the excipients; diabetic pre-coma; renal failure or renal dysfunction (creatinine clearance < 60 mL/min); acute conditions with the potential to alter renal function such as dehydration, severe infection or shock; intravascular administration of iodinated contrast materials; acute or chronic disease which may cause tissue hypoxia such as cardiac failure, recent myocardial infarction, respiratory failure, pulmonary embolism, shock, acute significant blood loss, sepsis, gangrene or pancreatitis; elective major surgery; severe hepatic insufficiency; acute alcohol intoxication; alcoholism; and lactation.

PBS listing

Information regarding PBS listing details is not available in the provided source documents.

Regulatory history

DIAXEMET XR was first listed on the Australian Register of Therapeutic Goods on 16 October 2020. The brand is available in six registered variants: 500 mg and 750 mg and 1000 mg formulations in both blister pack and bottle pack presentations.