Insulin Degludec: Uses, Mechanism, and Side Effects

People managing type 2 diabetes often look for insulin options with a steady, predictable action profile. Insulin degludec is a long-acting insulin analog that has been studied extensively and is available in an FDA-approved combination product.

Key takeaways

• Insulin degludec is a long-acting human insulin analog that regulates glucose metabolism.
• It is approved as part of Xultophy 100/3.6, a combination with liraglutide, for adults with type 2 diabetes.
• Xultophy 100/3.6 carries a boxed warning.
• More than 250 clinical trials have registered work involving insulin degludec.
• Reported reactions center on blood glucose changes and gastrointestinal symptoms.

What Insulin Degludec Is

Insulin degludec belongs to the insulin analog drug class. It lowers blood glucose by stimulating glucose uptake in muscle and fat tissue and by inhibiting glucose production in the liver. It also reduces the breakdown of fat and protein while supporting protein synthesis in the body.

What Insulin Degludec Is Approved For

Insulin degludec is approved in combination with liraglutide, a GLP-1 receptor agonist, under the brand name Xultophy 100/3.6. This combination is indicated alongside diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It is not recommended for treating diabetic ketoacidosis and has not been studied alongside prandial insulin. The product also should not be combined with other liraglutide-containing medications or other GLP-1 receptor agonists. Xultophy 100/3.6 carries a boxed warning.

What the Evidence Shows

More than 250 clinical trials have registered research involving insulin degludec. One completed phase 3 trial examined its efficacy and safety in children and adolescents with type 1 diabetes mellitus. Another completed trial compared the drug's effects on shifting patients from twice-daily insulin glargine or detemir to once-daily insulin degludec in type 1 diabetes.

Reported Side Effects

Reported side effect data reflect adverse event reports, not confirmed rates of incidence or causation. The most frequently reported reactions involve blood glucose fluctuations, including increased blood glucose (3,929 reports), decreased blood glucose (1,336), and hypoglycaemia (1,007). Gastrointestinal symptoms are also commonly reported, including nausea (1,601), vomiting (1,069), and diarrhoea (1,038). Reports of drug ineffectiveness (1,054) and off-label use (1,050) were also noted among the top reported terms.