SITAGLO-MET

What it is

SITAGLO-MET is a film-coated tablet combining sitagliptin (as hydrochloride monohydrate) 50 mg with metformin hydrochloride in three strengths: 500 mg, 850 mg, or 1000 mg.

Approved indications

— Treatment of 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 daily 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 daily 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, metformin can be used as monotherapy. The usual starting dose is one tablet of 500 mg or 850 mg once daily, given during or after meals. The maximum recommended dose 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 with high mortality in the absence of prompt treatment, and reported cases in patients on metformin 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. 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. Metformin induces a reduction in thyrotropin 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.

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 or diabetic ketoacidosis; hypersensitivity to metformin hydrochloride or to any of the excipients; diabetic pre-coma; renal failure or renal dysfunction with creatinine clearance less than 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

SITAGLO-MET is registered on the ARTG in three strengths: 50/500 mg (first listed 2024-09-24), 50/850 mg (first listed 2024-09-24), and 50/1000 mg (first listed 2024-09-24). PBS listing details are not available in the provided source documents.

Regulatory history

SITAGLO-MET was first listed on the Australian Register of Therapeutic Goods on 24 September 2024 in three film-coated tablet strengths containing sitagliptin 50 mg with metformin hydrochloride 500 mg, 850 mg, or 1000 mg.