Treatment of diabetes – Medication for NIDDM

Suphonylureas:

e.g: Tolbutamide, Glibenclamide

Their principle action is to increase insulin secretion in response to glucose and other secretagogues

Mechanism of action:

• Close ATP-sensitive potassium channels on the Β-cell membrane
• The resulting depolarisation promotes calcium influx, which is a signal for insulin release

When used?

• Are ineffective in patients without a functional Β-cell mass
• Should be avoided in young ketotic patients (who require early insulin therapy)
• Contraindicated in pregnancy

Other points:

• Should be used with care in patients with liver disease and only those primarily excreted by the liver should be used in those patients with renal impairment.
• All encourage weight gain (therefore, are not the first choice for obese patients)

Drug interactions/side-effects:

• Bind to circulating albumin and, therefore, may be displaced by other drugs
• Interact with warfarin
• Hypoglycaemia is the most common and dangerous side-effect

Biguanides:

e.g: Metformin

Unclear mechanism, but:

• They reduce gluconeogenesis
• This suppresses hepatic glucose output
• Thereby, increasing insulin sensitivity

Benefits:

• Rarely induces hypoglycaemia
• Doesn’t induce weight gain

Side-effects:

• Anorexia
• Epigastric discomfort
• Diarrhoea
• Lactic acidosis in those with liver/renal impairment

α-glucosidase inhibitors:

e.g: Acarbose

Mechanism of action:

• Inhibits the enzymes which are responsible for the breakdown of CHOs in the intestine
• This results in poor absorption of dietary CHO and a reduced postprandial rise in blood glucose

Side-effects:

• Abdominal discomfort
• Flatulence
• Diarrhoea