Generic Name:Metformin (met-for´min)
Brand Name:Glucophage, Glucophage XR
Classifications: hormone and synthetic substitute; antidiabetic; biguanide
Pregnancy Category: B
500 mg, 850 mg tab-lets; 500 mg sustained release
Biguanide oral hypoglycemic agent. Unlike sulfonylureas, biguanides do not stimulate the release of insulin from the beta cells of the pancreas. Mechanism of action is thought to be due to both increasing the binding of insulin to its receptor and potentiating insulin action.
Improves tissue sensitivity to insulin, increases glucose transport into skeletal muscles and fat, and suppresses gluconeogenesis and hepatic production of glucose, thus lowering blood glucose levels.
Treatment of type 2 diabetes mellitus in patients not controlled with diet alone. May be used with an oral sulfonylurea.
Hypersensitivity to metformin; renal, hepatic, or cardiopulmonary insufficiency; alcoholism; concurrent infection.
Route & Dosage
Type 2 Diabetes Mellitus
adult: PO Start with 500 mg q.d. to t.i.d. or 850 mg q.d. to b.i.d. with meals, may increase by 500–850 mg/d every 1–3 wk (max: 2550 mg/d); or start with 500 mg sustained release with p.m. meal, may increase by 500 mg/d at p.m. meal q wk (max: 2000 mg/d)
- Withhold metformin 48 h before and 48 h after receiving IV contrast dye.
- Give with or shortly after main meals.
- Make dose increment, if needed, at 2–3-wk intervals.
- Consider reduction of dose with concurrent cimetidine therapy.
- Store at 15°–30° C (59°–86° F).
CNS:Headache, dizziness, agitation, fatigue.
Assessment & Drug Effects
- Lab tests: Obtain baseline and periodic kidney and liver function tests; drug contraindicated in the presence of renal or hepatic insufficiency.
- Monitor blood glucose and HbA1C, and lipid profile periodically.
- Monitor known or suspected alcoholics carefully for decreased liver function.
- Monitor cardiopulmonary status throughout course of therapy; cardiopulmonary insufficiency may predispose to lactic acidosis.
Patient & Family Education
- Be aware that hypoglycemia is not a risk when drug is taken in recommended therapeutic doses unless combined with other drugs which lower blood glucose.
- Report to physician immediately S&S of infection, which increase the risk of lactic acidosis (e.g., abdominal pains, nausea and vomiting anorexia).
- Do not breast feed while taking this drug without consulting physician.