From the Guidelines
Metformin is the most accepted first-line medication for the initiation of treatment in type 2 diabetes. The typical starting dose is 500 mg once or twice daily with meals, gradually increasing to a target dose of 1000-2000 mg daily divided into two doses to minimize gastrointestinal side effects, as recommended by the American Diabetes Association standards of medical care in diabetes 1. Metformin works by decreasing hepatic glucose production, reducing intestinal glucose absorption, and improving insulin sensitivity. It is preferred as initial therapy because it effectively lowers blood glucose without causing hypoglycemia when used alone, is weight-neutral or may promote modest weight loss, has cardiovascular benefits, and is available as an inexpensive generic medication.
Key Considerations
- Common side effects include diarrhea, nausea, and abdominal discomfort, which can be minimized by taking it with food and slowly titrating the dose.
- Metformin should be used cautiously in patients with renal impairment (eGFR <45 mL/min) and is contraindicated in severe renal dysfunction (eGFR <30 mL/min), liver disease, or conditions that may cause lactic acidosis, as noted in the management of hyperglycemia in type 2 diabetes position statement 1.
- A patient-centered approach should be used to guide the choice of pharmacologic agents, including assessment of efficacy, hypoglycemia risk, effect on weight, side effects, cost, and patient preferences, as recommended by the ADA/European Association for the Study of Diabetes position statement 1.
Additional Recommendations
- The Diabetes Prevention Program Outcomes Study found that long-term users of metformin may develop vitamin B12 deficiency, and periodic testing of vitamin B12 levels should be considered in metformin users, especially those with anemia or peripheral neuropathy 1.
- If the patient does not tolerate or has a contraindication to metformin, another option should be considered, and a table detailing characteristics of all available glucose-lowering agents in the United States may guide individualized treatment choices 1.
From the Research
Treatment Options for Type 2 Diabetes
The most accepted drug for the initiation of treatment in type 2 diabetes is metformin, as it is often considered the cornerstone of initial management 2.
Alternative Treatment Options
Other treatment options include:
- Sulphonylureas
- Insulin
- Thiazolidinediones
- α-glucosidase inhibitors
- Glucagon-like peptide-1 agonists
- Dipeptidyl peptidase 4 inhibitors
- The amylin receptor agonist pramlintide 2
- Pioglitazone, which can be administered in combination with metformin, sulfonylureas, exenatide, dipeptidyl peptidase 4 (DPP-4) inhibitors or insulin 3
Insulin Therapy
Insulin therapy can also be considered as an initial treatment option, especially for newly diagnosed, treatment-naive patients with type 2 diabetes, as it has been shown to be effective, safe, and well accepted 4.
Key Considerations
When selecting a treatment option, it is essential to consider the patient's specific needs and to help them overcome barriers, including fears of injection pain, public embarrassment, and hypoglycemia risk 5.