Drug Groups

approved

Description

Gliclazide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the sulfonylurea class of insulin secretagogues, which act by stimulating β cells of the pancreas to release insulin. Sulfonylureas increase both basal insulin secretion and meal-stimulated insulin release. Medications in this class differ in their dose, rate of absorption, duration of action, route of elimination and binding site on their target pancreatic β cell receptor. Sulfonylureas also increase peripheral glucose utilization, decrease hepatic gluconeogenesis and may increase the number and sensitivity of insulin receptors. Sulfonylureas are associated with weight gain, though less so than insulin. Due to their mechanism of action, sulfonylureas may cause hypoglycemia and require consistent food intake to decrease this risk. The risk of hypoglycemia is increased in elderly, debilitated and malnourished individuals. Gliclazide has been shown to decrease fasting plasma glucose, postprandial blood glucose and glycosolated hemoglobin (HbA1c) levels (reflective of the last 8-10 weeks of glucose control). Gliclazide is extensively metabolized by the liver; its metabolites are excreted in both urine (60-70%) and feces (10-20%).

Indication

For the treatment of NIDDM in conjunction with diet and exercise.

Pharmacology

Gliclazide is a second generation sulphonylurea which acts as a hypoglycemic agent. It stimulates β cells of the islet of Langerhans in the pancreas to release insulin. It also enhances peripheral insulin sensitivity. Overall, it potentiates insulin release and improves insulin dynamics.

Toxicity

LD₅₀=3000 mg/kg (orally in mice). Gliclazide and its metabolites may accumulate in those with severe hepatic and/or renal dysfunction. Symptoms of hypoglycemia include: dizziness, lack of energy, drowsiness, headache and sweating.

Affected Organisms

Biotransformation

Extensively metabolized in the liver. Less than 1% of the orally administered dose appears unchanged in the urine. Metabolites include oxidized and hydroxylated derivates, as well as glucuronic acid conjugates.

Absorption

Rapidly and well absorbed but may have wide inter- and intra-individual variability. Peak plasma concentrations occur within 4-6 hours of oral administration.

Half Life

10.4 hours. Duration of action is 10-24 hours.

Protein Binding

94%, highly bound to plasma proteins

Elimination

Metabolites and conjugates are eliminated primarily by the kidneys (60-70%) and also in the feces (10-20%).

External Links