Sitagliptin — NZ Medication Guide
📋 Reviewed by a Registered Pharmacist NZ — This information is for general educational purposes only and does not replace professional medical advice. Always consult your doctor or pharmacist before starting, stopping, or changing any medication.
What is Sitagliptin?
Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor used for the management of type 2 diabetes mellitus. This medication is funded by Pharmac under Special Authority for type 2 diabetes combination therapy.
What is Sitagliptin Used For?
Sitagliptin is used as an add-on therapy to metformin, sulfonylureas, insulin, or other antidiabetic medicines to improve glycaemic control in type 2 diabetes mellitus.
How Does Sitagliptin Work?
Sitagliptin inhibits the enzyme DPP-4, which normally breaks down the incretin hormones GLP-1 and GIP. By blocking DPP-4, sitagliptin prolongs incretin activity — stimulating glucose-dependent insulin release from the pancreas and suppressing glucagon secretion after meals. This lowers post-meal blood glucose with a low risk of hypoglycaemia.
How to Take Sitagliptin
Taken once daily (100 mg) with or without food. Dose reduction required in moderate to severe renal impairment (eGFR <45 mL/min — reduce to 50 mg/day; eGFR <30 — 25 mg/day).
Common Side Effects of Sitagliptin
- Upper respiratory tract infections (nasopharyngitis)
- Headache
- Nausea
- Diarrhoea
Serious Side Effects — Seek Medical Attention
Contact your doctor or call 111 immediately if you experience any of the following:
- Pancreatitis (rare — discontinue if abdominal pain develops)
- Severe allergic reactions including angioedema and urticaria
- Joint pain (arthralgia — sometimes severe)
- Bullous pemphigoid (rare skin blistering — especially in elderly patients)
- Hypoglycaemia (when combined with sulfonylureas or insulin)
Drug Interactions
Sitagliptin may interact with other medicines. Always inform your doctor and pharmacist of all medications you are taking. Key interactions include:
- Sulfonylureas and insulin (increased hypoglycaemia risk — consider dose reduction of the sulfonylurea/insulin)
New Zealand Prescribing Information
Sitagliptin (Januvia® 100 mg, 50 mg, 25 mg tablets) is funded by Pharmac under Special Authority as add-on therapy for type 2 diabetes when metformin and/or a sulfonylurea is insufficient. It has a low risk of hypoglycaemia and is generally well tolerated. The fixed-dose combination with metformin (Janumet®) is also available.
Frequently Asked Questions
What is special about DPP-4 inhibitors like sitagliptin?
They lower blood glucose in a glucose-dependent manner — meaning they only stimulate insulin release when glucose levels are high. This means the risk of hypoglycaemia (low blood sugar) is very low compared to sulfonylureas.
Does sitagliptin cause weight gain?
No — sitagliptin is generally weight-neutral, which is an advantage over some other diabetes medicines such as sulfonylureas and insulin.
⚠️ Disclaimer: This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or a qualified health provider. In New Zealand, medication availability and funding may vary — check with Pharmac or your pharmacist for current information.
Reviewed by a Registered Pharmacist NZ
References & Further Information
The following New Zealand and international resources were used to inform this page: