What is the first-line pharmacologic therapy for type 2 diabetes?

• A. Metformin
• B. Sulfonylureas
• C. Insulin
• D. GLP-1 receptor agonists

Answer: (A)

Metformin is chosen first because it lowers glucose safely and effectively with a favorable balance of benefits, risks, and cost. It works mainly by reducing hepatic glucose production and improving insulin sensitivity in muscles, which helps lower both fasting and postprandial glucose without driving up insulin levels too much. This translates to meaningful HbA1c reductions while avoiding hypoglycemia when used alone. It also tends to be weight-neutral or even associated with modest weight loss, an important consideration in type 2 diabetes. In addition, there is strong long-term evidence supporting its cardiovascular safety, and it is inexpensive and widely available. Start after lifestyle changes, and monitor kidney function since metformin dosing is adjusted or avoided with impaired renal function. Other options have drawbacks for initial therapy: sulfonylureas can cause hypoglycemia and weight gain; insulin requires injections and is typically reserved for more advanced disease; GLP-1 receptor agonists are effective and can aid weight loss but are injectable and often more costly, making them less suitable as the default first choice.