Adult: Initially, 2.5-5 mg daily, may ↑wkly by increments of 2.5 mg daily, up to 15 mg daily. Doses >10 mg daily should be given in 2 divided doses. Max: 20 mg daily.
Elderly: Initially, 1.25-2.5 mg daily, may ↑by 1.25-2.5 mg daily every 1-3 wk, if needed.
Glibenclamide exerts pancreatic and extrapancreatic actions. It stimulates an ↑in insulin release by the pancreatic β-cells. It may also reduce hepatic gluconeogen and glycogenolysis. Increased glucose uptake in the liver and utilization in the skeletal muscles.
Blood dyscrasias (reversible), liver dysfunction, hypoglycaemia, GI symptoms, allergic skin reactions. Potentially Fatal: Prolonged hypoglycaemia seen in elderly or debilitated patients with hepatic or renal diseases.
Increased risk of hypoglycaemia when used with β-blockers. Additive hypoglycaemic effect with insulin and other antidiabetic drugs. Metabolism may be reduced by chloramphenicol and cimetidine. Increased hypoglycemic effect when used with cyclic antidepressants, pegvisomant, corticosteroids, salicylates, sulfonamide derivatives (except sulfacetamide) or fibric acid derivatives. Concurrent use may ↑serum levels of ciclosporin. Increased serum levels when used with fluconazole.
Metabolism of glibenclamide may be increased when used with rifampin. Concurrent use with coumarin derivatives may cause changes in INR. Concurrent admin with chloestyramine resin may lead to reduced absorption of glibenclamide. Serum levels may be reduced by colesevelam.
Therapeutic efficacy may be diminished by luteinizing-hormone releasing hormone analogs. Concurrent use may ↑adverse effects of phenytoin. Quinolone antibiotics may affect the efficacy of glibenclamide; monitor blood sugar levels.
Hypoglycaemic effect may be reduced by somatropin.
Potentially Fatal: Increased risk of liver toxicity when used with bosentan; avoid concurrent use.
Duration: 24 hr. Absorption: Readily absorbed from the GI tract (oral); peak plasma concentrations after 2-4 hr. Distribution: Protein-binding: Extensive. Metabolism: Hepatic; converted to very weakly active metabolite. Excretion: Urine (50%); faeces (50%).