Biguanides

Metformin is a commonly used medication for the management of type II diabetes.  Metformin is also used in the treatment of polycystic ovarian syndrome.  Metformin works by decreasing hepatic glucose production, increasing tissue sensitivity to glucose, and decreasing glucose absorption from the gut.  Nausea and gastrointestinal upset are common on initiation of the metformin, so dosing is gradually increased to therapeutic level.  Lactic acidosis is also a potential side effect, and metformin should be discontinued in renal dysfunction. Metformin does not cause hypoglycemia.

Class Drugs

• Metformin

Class Mechanism of Action

Decreased hepatic production of glucose

Increased peripheral tissue sensitivity to insulin

Decreases intestinal absorption of glucose

Class Applications

Type II Diabetes Mellitus

• First line treatment

• Weight loss secondary benefit

Polycystic Ovarian Syndrome

• Decreases insulin resistance, which improves ovulation and fertility

Class Adverse Effects

Lactic Acidosis

• Contraindicated in renal dysfunction, so should be discontinued when renal insufficiency is present or may develop

• Temporarily stop metformin after IV contrast administration

Nausea and gastrointestinal upset

• Generally present on initiation and dosing changes but improves with time

Drug Table

Drug Name	Application	Comments	Image
Metformin			"Mets Mascot" "Form"