GLUCOPHAGE (METFORMIN)

DRUG NAME: metformin

USE: Oral antidiabetic agent

This medicine is indicated for non-insulin dependent (type 2) diabetes. It is also used in some cases of polycystic ovary syndrome (unlicensed use).

It works by inhibiting glucose production (gluconeogenesis) and increasing peripheral utilisation of glucose.

Metformin is the drug of choice in overweight patients in whom strict dieting has been unsuccessful or has failed to control diabetes.

Hypoglycaemia (low blood glucose) does not usually occur with metformin.

Contrainidcations:

- kidney impairment (may provoke lactic acidosis)
- recent heart attack
- liver impairment
- general anaesthesia (stop 2 days before anaesthesia)
- pregnancy
- breast feeding

Side effects:

Gastro-intestinal side-effects are common initially (anorexia, nausea, vomiting, diarrhoea, abdominal pain). May also cause a metallic taste.

Rarely: lactic acidosis, decreased vitamin B12 absorption, itch, weals, hepatitis.

Interactions:

- enhances anticoagulant effect of warfarin
- increases risk of lactic acidosis with alcohol
- risk of hypoglycaemia with cimetidine