MOUNJARO

What it is

MOUNJARO is tirzepatide solution for injection, available as single-dose vials and pre-filled pens, as well as multiple-dose pre-filled pens (KwikPen). MOUNJARO is a clear, colourless to slightly yellow, sterile solution for subcutaneous administration. Tirzepatide is a long-acting GIP and GLP-1 receptor agonist. It is an amino acid sequence with a C20 fatty diacid moiety that enables albumin binding and prolongs half-life.

Approved indications

— Type 2 diabetes mellitus in adults with insufficiently controlled type 2 diabetes mellitus as an adjunct to diet and exercise, as monotherapy when metformin is not tolerated or contraindicated. — Type 2 diabetes mellitus in adults with insufficiently controlled type 2 diabetes mellitus in addition to other medicinal products for the treatment of type 2 diabetes. — Chronic weight management as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index of ≥ 30 kg/m² (obesity) or ≥ 27 kg/m² to < 30 kg/m² (overweight) in the presence of at least one weight-related comorbid condition such as hypertension, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes mellitus. — Obstructive sleep apnoea, for the treatment of moderate to severe obstructive sleep apnoea in adults with obesity.

Dosing overview

The starting dose of tirzepatide is 2.5 mg once weekly. After 4 weeks, increase the dose to 5 mg once weekly. If needed, dose increases can be made in 2.5 mg increments after a minimum of 4 weeks on the current dose. The recommended doses are 5 mg, 10 mg and 15 mg. The maximum dose of tirzepatide is 15 mg once weekly. MOUNJARO can be injected at any time of the day, with or without meals. Inject tirzepatide subcutaneously in the abdomen or thigh. When tirzepatide is added to existing therapy of a sulfonylurea and/or insulin, a reduction in the dose of sulfonylurea or insulin may be considered to reduce the risk of hypoglycaemia.

Key safety warnings

MOUNJARO should not be used in patients with type 1 diabetes mellitus or for the treatment of diabetic ketoacidosis. Tirzepatide has not been studied in patients with a history of pancreatitis and should be used with caution with these patients. Acute pancreatitis has been reported in patients treated with tirzepatide. Patients should be informed of the symptoms of acute pancreatitis. If pancreatitis is suspected, tirzepatide should be discontinued. If the diagnosis of pancreatitis is confirmed, tirzepatide should not be restarted. Tirzepatide has been associated with gastrointestinal adverse reactions, which include nausea, vomiting, and diarrhoea. These events may lead to dehydration, which could cause a deterioration in renal function, including acute renal failure. Patients treated with tirzepatide should be advised of the potential risk of dehydration, particularly in relation to gastrointestinal adverse reactions and take precautions to avoid fluid depletion. Tirzepatide has not been studied in patients with severe gastrointestinal disease, including severe gastroparesis, and should be used with caution in these patients. Events related to impaired gastric emptying, including severe gastroparesis, have been reported. Monitor and consider dose modification or discontinuation in patients who develop severe gastrointestinal symptoms while on treatment. Events related to malnutrition have been reported, including severe, in patients receiving tirzepatide. Risks associated with malnutrition include, but are not limited to, vitamin and mineral deficiency, protein deficiency, and low body weight. Balanced nutritional support should be considered. Discontinuation should be considered for severe or persistent cases. Patients receiving tirzepatide in combination with an insulin secretagogue (for example, a sulfonylurea) or insulin may have an increased risk of hypoglycaemia. The risk of hypoglycaemia may be lowered by a reduction in the dose of the insulin secretagogue or insulin.

Contraindications

MOUNJARO is contraindicated in patients with known hypersensitivity to tirzepatide or any of the excipients.

Regulatory history

The TGA approved Mounjaro (tirzepatide) on 22 December 2022 for the treatment of adults with insufficiently controlled type 2 diabetes mellitus as an adjunct to diet and exercise, either as monotherapy or in addition to other medicinal products. Pre-filled pen formulations (2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg) were first listed on the ARTG on 2022-12-23, with single-dose vials added on 2023-07-10 and multiple-dose KwikPen formulations on 2024-06-19. This medicinal product is subject to additional monitoring in Australia due to approval of an extension of indications. In July 2023, PBAC did not recommend MOUNJARO for type 2 diabetes mellitus. In November 2024, PBAC did not recommend MOUNJARO for dual therapy in combination with metformin for inadequately controlled type 2 diabetes mellitus with comorbid severe obesity or Aboriginal/Torres Strait Islander populations, citing high incremental cost-effectiveness ratio, inadequately justified rationale, and uncertain cost-effectiveness; a revised economic model and price reduction were required. In July 2025, PBAC deferred consideration of MOUNJARO for type 2 diabetes mellitus in adults with inadequately controlled type 2 diabetes mellitus, deferring for further discussions on pricing and financial risk.