Synopsis
Choose incretin-based treatment safely, distinguish DPP-4 from GLP-1 and dual GIP–GLP-1 therapy, and monitor benefit, pregnancy, pancreatitis and perioperative risk.
- DPP-4 inhibitors prolong endogenous incretin action, are weight neutral and have low hypoglycaemia risk alone; their glucose-lowering effect is modest compared with injectable GLP-1 or tirzepatide.
- GLP-1 receptor agonists increase glucose-dependent insulin, suppress glucagon, slow gastric emptying and promote satiety; tirzepatide activates both GIP and GLP-1 receptors.
- Use the February 2026 NICE NG28 phenotype-based algorithm and licensed indication; diabetes and weight-management brands, doses and eligibility are not interchangeable.
Key red flags
Severe persistent epigastric pain that may radiate to the back, commonly with nausea or vomiting, needs immediate medicine cessation and urgent assessment; common nausea should not obscure this pattern.
Investigation priorities
Measure glycaemic response and guide co-therapy adjustment.
Management branches
Low-hypoglycaemia oral treatment is appropriate within NICE NG28.
- Review renal and hepatic function, heart failure, pancreatitis history, co-prescribed incretin therapy and the desired size of glucose reduction before selecting a specific agent.
- Use the current BNF dose for kidney function, explain that weight effect is neutral and reduce insulin or sulfonylurea only when glucose patterns justify it.
Key medicines
DPP-4 inhibitorUse the licensed once- or twice-daily regimen with product-specific renal adjustment.
GLP-1 receptor agonistStart at the product's introductory dose and escalate only at licensed intervals.