Brands, Medical Use, Clinical Data
Drug Category
- Hypoglycemic Agents
- Sulfonylureas
Dosage Forms
Brands / Synonyms
Aglicid; Apo-Tolbutamide; Arkozal; Artosin; Artozin; Butamid; Butamide; Diaben; Diabetamid; Diabetol; Diabuton; Diasulfon; Dirastan; Dolipol; Drabet; Glyconon; Ipoglicone; Mobenol; Novo-Butamide; Orabet; Oralin; Orezan; Orinase; Orinase Diagnostic; Orinaz; Oterben; Pramidex; Rastinon; Restinon; Sk-tolbutamide; Tol-Tab; Tolbusal; Tolbutamid; Tolbutamide; Toluina; Tolumid; Toluvan; Tolylsulfonylbutylurea; Willbutamide
Indications
Used as an oral hypoglycemic agent in non-insulin-dependent (type 2) Diabetes Miletus with adult onset.
Pharmacology
Tolbutamide, a second-generation sulfonylurea antidiabetic agent, is used with diet to lower blood glucose levels in patients with diabetes mellitus type II. Tolbutamide is twice as potent as the related second-generation agent glipizide. Tolbutamide lowers blood sugar by stimulating the pancreas to secrete insulin and helping the body use insulin efficiently. The pancreas must be able to produce insulin for this drug to work.
Mechanism of Action
Sulfonylureas lower blood glucose in patients with type 2 diabetes by directly stimulating the acute release of insulin from functioning beta cells of pancreatic islet tissue by an unknown process that involves a sulfonylurea receptor (receptor 1) on the beta cell. Sulfonylureas inhibit the ATP-potassium channels on the beta cell membrane and potassium efflux, which results in depolarization and calcium influx, calcium-calmodulin binding, kinase activation, and release of insulin-containing granules by exocytosis, an effect similar to that of glucose.
Absorption
Well absorbed. Absorption is unaltered if taken with food but is increased with high pH.
Toxicity
Oral, mouse: LD50 = 2600 mg/kg
Biotrnasformation / Drug Metabolism
Hepatic
Contraindications
You should not take tolbutamide if you have had an allergic reaction to it. Tolbutamide should not be taken if you are suffering from diabetic ketoacidosis (a life-threatening medical emergency caused by insufficient insulin and marked by excessive thirst, nausea, fatigue, pain below the breastbone, and fruity breath). In addition, Tolbutamide should not be used as the sole therapy in treating type 1 (insulin-dependent) diabetes.
Drug Interactions
Sulphinpyrazone, a drug used as an antithrombotic agent and inhibitor of platelet aggregation has a potent side effect as a uricosuric agent. The uricosuric side effect increases the urinary excretion of uric acid effectively blocking hepatic conjugation. Tests show that Sulphinpyrazone’s effect on Tolbutamide is a reduction of liver function to 60% of normal without interfering with protein binding. Taking alpha-lipoic acid or chromium with tolbutamide may require a change in the drug's dosage. Use ephedra with caution when taking tolbutamide; ephedra can raise blood sugar levels.
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