Januvia (Sitagliptin): Uses, Safety and Interactions

What Januvia is used for

Januvia 100 mg is an oral film-coated tablet containing sitagliptin. This DPP-4 inhibitor helps the body regulate insulin and glucagon in response to meals. The reviewed EU and UK information covers adults with type 2 diabetes, alongside diet and exercise. It can be prescribed alone when metformin is unsuitable, or with specified other diabetes treatments when control remains inadequate. It is not intended for type 1 diabetes or diabetic ketoacidosis.

Why kidney function matters

Sitagliptin is mainly removed through the kidneys. Kidney function therefore affects which tablet strength is appropriate: a 100 mg product is not suitable for every patient or every stage of kidney disease. The prescriber should assess renal function and review the doses of accompanying diabetes medicines. Do not split or substitute strengths on the basis of a general web summary. Possible adverse effects include headache and gastrointestinal symptoms; low blood sugar is especially important when insulin or a sulfonylurea is also used.

Warning symptoms to recognise

Persistent severe abdominal pain, sometimes spreading to the back, needs urgent assessment for pancreatitis. Severe allergy, facial or throat swelling, breathing difficulty or a widespread blistering or peeling rash also requires urgent care. Blistering skin disease called bullous pemphigoid has been reported after marketing. A previous episode of pancreatitis and new skin changes should be discussed with the treating clinician. Serious reactions are different from mild, self-limited stomach symptoms and should not be dismissed.

Interactions and pregnancy

Sitagliptin has relatively few clinically important pharmacokinetic interactions, but that does not make every combination safe. Insulin and sulfonylureas can raise hypoglycaemia risk and may need prescriber-led adjustment. Sitagliptin slightly increases digoxin exposure; patients susceptible to digoxin toxicity may need closer monitoring. Strong CYP3A4 inhibitors could matter more in severe kidney impairment, although that situation has not been adequately studied clinically. Current EU and UK information advises against use during pregnancy and breastfeeding because human evidence is inadequate. Review pregnancy plans and the complete medicine list with a clinician, and follow the local leaflet rather than applying dosing instructions from another country.

Sources

• Januvia — EU product information, sitagliptin tablets — Current English EU SmPC and package leaflet accessed 30 October 2026
• Januvia 100 mg film-coated tablets — UK SmPC — Merck Sharp and Dohme; text revision 12 October 2023; accessed 30 October 2026

Source check: 30 October 2026. This records a source check, not a clinical review by a doctor or pharmacist. Follow the current leaflet supplied with your medicine and seek professional advice for personal treatment.