Gliclazide

Class	Oral hypoglycaemic
Chemistry	Second generation sulfonylurea
Routes of administration	Oral only
Absorption	Completely absorbed, oral bioavailability 97%
Solubility	pKa=5.8; basically insoluble in water; but at least slightly soluble in lipid and ethanol
Distribution	VOD= 0.2-0.4 L/kg; 85-97% protein bound
Metabolism	Extensive hepatic metabolism
Elimination	Only 4% of the drug is renally eliminated
Time course of action	Half life 11 hrs
Target receptor	Sulfonylurea receptors (SUR1 and SUR2), which form a part of the ATP-sensitive potassium channel complex on pancreatic β-cells
Mechanism of action	By binding to the ATP-sensitive K channel, sulfonylureas act like ATP (i.e. same as a rise in blood glucose), closing the channel and stopping the efflux of potassium from the cell, which promotes depolarisation. The depolarisation then leads to insulin release
Clinical effects	Hypoglycaemia, but also: - undesirable severe hypoglycaemia - hypokalemia - secondary failure of therapy (as beta-cells burn out) - erythema multiforme - exfoliative dermatitis - photosensitivity
Literature reference	Sola et al, 2015
CICM details of understanding	Level 3
Mentioned around Deranged Physiology
Related SAQs