Chlorpropamide

The sulfonylureas act mainly by augmenting insulin secretion and consequently are effective only when some residual pancreatic beta-cell activity is present. During long-term administration, they also have an extrapancreatic action. Chlorpropamide also potentiates the action of small or residual amounts of circulating vasopressin. It likely acts directly on the kidney to enhance V2-receptor-mediated antidiuresis.

Adult

For partial central DI: 125-500 mg daily

Renal adjustment

Use with care in mild to moderate renal impairment, because of the hazard of hypoglycaemia; use the lowest dose that adequately controls blood glucose. Avoid where possible in severe renal impairment.

Hepatic adjustment

Manufacturers advise avoid in severe impairment (increased risk of hypoglycaemia).

Geriatric

Prescription potentially inappropriate (STOPP criteria) if prescribed a long-acting sulfonylurea in type 2 diabetes mellitus (risk of prolonged hypoglycaemia).

• Presence of ketoacidosis
• Severe hepatic impairment
• Severe renal impairment