DIAFORMIN ALPHAPHARM XR

What it is

DIAFORMIN ALPHAPHARM 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, 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. Five hundred milligrams 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 (high mortality in the absence of prompt treatment), 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. 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. 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. Vitamin B12 deficiency is common. Consideration of such aetiology is recommended if a patient presents with megaloblastic anaemia. Therefore, serum B12 levels should be appropriately monitored or periodic parenteral B12 supplementation should be considered.

Contraindications

Contraindications include 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 less than 60 mL/min); acute conditions with the potential to alter renal function such as dehydration, severe infection, 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, pancreatitis; elective major surgery; severe hepatic insufficiency; acute alcohol intoxication; alcoholism; and lactation.

Regulatory history

DIAFORMIN ALPHAPHARM XR metformin hydrochloride 1000 mg modified release tablet was first listed on the ARTG on 10 September 2015. DIAFORMIN ALPHAPHARM XR metformin hydrochloride 500 mg modified release tablet was first listed on the ARTG on 10 September 2015.