Common name in Nepal: Sitagliptin (Januvia, Istavel), Vildagliptin (Galvus), Linagliptin (Trajenta), Teneligliptin (Tenepride)
What Are DPP-4 Inhibitors?
DPP-4 inhibitors, often called "gliptins," are a class of oral diabetes medications that work through the body's natural gut hormone (incretin) system. They are popular because they are simple to take (usually once daily), are weight-neutral, and carry a very low risk of hypoglycemia on their own.
Mechanism of Action
After eating, the intestine releases hormones called incretins — mainly GLP-1 and GIP — which stimulate the pancreas to release insulin in a glucose-dependent way (only when blood sugar is elevated) and suppress glucagon (the hormone that raises blood sugar). Normally, these incretin hormones are broken down within one to two minutes by an enzyme called DPP-4. DPP-4 inhibitors block this enzyme, allowing the body's own incretin hormones to remain active longer after meals, which improves insulin release and lowers glucagon specifically around mealtimes — without directly stimulating insulin release when blood sugar is already normal.
Benefits
DPP-4 inhibitors typically lower HbA1c by about 0.5 to 0.8 percentage points, a more modest effect than metformin or sulfonylureas but with a very favorable side-effect profile: minimal hypoglycemia risk as monotherapy, no weight gain, and good general tolerability, making them a common add-on choice, particularly in older adults.
Side Effects
Generally mild, well-tolerated profile — the most common side effects are upper respiratory tract infections, headache, and mild gastrointestinal upset (nausea, diarrhea), which are usually transient.
Joint pain has been reported with this class, including rare cases of severe, disabling joint pain that resolved after stopping the drug — patients experiencing new or worsening joint symptoms should mention this to their doctor.
Acute pancreatitis is a rare but recognized concern; a direct causal link has not been firmly established, but patients should seek prompt care for persistent, severe abdominal pain, which can be an early sign.
Skin reactions, including a rare blistering skin condition called bullous pemphigoid, have been reported, more often described with certain gliptins and usually in older adults.
Unlike sulfonylureas or insulin, DPP-4 inhibitors do not typically cause hypoglycemia or weight gain when used alone, though the hypoglycemia risk increases when combined with a sulfonylurea or insulin.
Precautions
Most DPP-4 inhibitors (except linagliptin) require dose reduction in reduced kidney function, so renal function should guide dosing. Patients with a history of pancreatitis should discuss this with their doctor before starting. Anyone developing severe joint pain, unusual blistering skin rash, or persistent abdominal pain while on a gliptin should contact their doctor promptly rather than waiting for a routine follow-up.
Required Tests: Before and After Starting
Kidney function (creatinine/eGFR) should generally be checked before starting, since dosing for most gliptins depends on it. Liver function is sometimes checked at baseline as well. During treatment, HbA1c is typically checked every 3 to 6 months, and kidney function is periodically reassessed, particularly in older adults or those with pre-existing kidney disease.
Sources
ClinicSearch. "DPP-4 inhibitors in Type 2 Diabetes mellitus – A Panoramic Review."
Egan AG, et al. "Pancreatic Safety of Incretin-Based Drugs — FDA and EMA Assessment." New England Journal of Medicine, 2014.
European Medicines Agency Summary of Product Characteristics for sitagliptin.
Béné J, et al. "Bullous pemphigoid and dipeptidyl peptidase IV inhibitors: a case-noncase study." British Journal of Dermatology, 2016.