Introduction

Sulfonylureas are oral hypoglycaemic drugs used in the management of type 2 diabetes mellitus. They work by increasing pancreatic insulin secretion and hence are only effective if functional B-cells are present.

Mechanism of action

They work by increasing pancreatic insulin secretion and hence are only effective if functional B-cells are present. On a molecular level they bind to an ATP-dependent K+(KATP) channel on the cell membrane of pancreatic beta cells.

Adverse effects

  • Hypoglycaemic episodes (more common with long-acting preparations such as chlorpropamide)
  • Weight gain

Rarer adverse effects
  • Hyponatraemia secondary to syndrome of inappropriate ADH secretion
  • Bone marrow suppression
  • Hepatotoxicity (typically cholestatic)
  • Peripheral neuropathy

Contraindications

Sulfonylureas should be avoided in breastfeeding and pregnancy.