Indications

Adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus when treatment with both Linagliptin and Metformin Hydrochloride is appropriate.

Pharmacology

Linagliptin: DPP-4 inhibitor. Prevents degradation of incretin hormones (GLP-1, GIP), increasing insulin secretion from pancreatic β-cells in a glucose-dependent manner and reducing glucagon secretion from α-cells.
Metformin Hydrochloride: Biguanide antihyperglycemic. Lowers basal and postprandial plasma glucose by decreasing hepatic glucose production, reducing intestinal absorption of glucose, and improving insulin sensitivity.

Dosage & Administration

Immediate-release tablets:
- Max dose: Linagliptin 2.5 mg + Metformin 1000 mg twice daily with meals.
- Starting dose:
  - If not on Metformin: Linagliptin 2.5 mg + Metformin 500 mg twice daily.
  - If already on Metformin: Linagliptin 2.5 mg + current Metformin dose twice daily.
  - If already on both: Switch to combination with same doses.
Extended-release tablets:
- Max dose: Linagliptin 5 mg + Metformin 2000 mg once daily with meal.
- Starting dose:
  - If not on Metformin: Linagliptin 5 mg + Metformin 1000 mg once daily.
  - If already on Metformin: Linagliptin 5 mg + similar Metformin dose once daily.
  - If already on immediate-release: Switch to extended-release with equivalent total daily dose.

Interactions

Cationic drugs (e.g., cimetidine, digoxin, morphine): May compete with Metformin for renal tubular secretion → monitor closely.
Carbonic anhydrase inhibitors (e.g., topiramate, acetazolamide): May increase risk of metabolic acidosis.
P-gp/CYP3A4 inducers (e.g., rifampin): Reduce Linagliptin exposure → alternative therapy recommended.
Drugs affecting glycemic control (e.g., corticosteroids, diuretics, estrogens, thyroid products): May cause hyperglycemia → monitor closely.

Contraindications

Side Effects

Pregnancy & Lactation

Precautions & Warnings

Lactic acidosis: Discontinue Metformin immediately if suspected.
Pancreatitis: Reported post-marketing; discontinue if suspected.
Temporarily stop before radiologic studies with contrast or major surgery.
Metformin may lower Vitamin B12 levels → monitor hematologic parameters annually.
Alcohol increases risk of lactic acidosis.
Patients should carry medical identification for diabetes emergencies.