Trade Names:Orinase- Tablets 500 mg
Trade Names:Orinase Diagnostic- Powder for injection 1 g (as sodium)/vialApo-Tolbutamide (Canada)
Decreases blood glucose by stimulating release of insulin from pancreas.
Orally administered tolbutamide is readily absorbed from the GI tract.
Tolbutamide has no p-amino group, cannot be acetylated; however, presence of p-methyl group makes it susceptible to oxidation. A major metabolite is 1-butyl-3-p-carboxy-phenylsulfonylurea (inactive).
Tolbutamide t ½ is 4.5 to 6.5 h.
Onset of action is 20 min.
Time to peak effect is 3 to 4 h.
Tolbutamide duration of action is 24 h.
Adjunct to diet to lower blood glucose in patients with non-insulin-dependent diabetes mellitus (type 2) whose hyperglycemia cannot be controlled by diet alone.IV form (tolbutamide sodium)
Aid in diagnosis of pancreatic islet cell adenoma.
Hypersensitivity to sulfonylureas; diabetes complicated by ketoacidosis with or without coma; sole therapy of insulin-dependent (type 1) diabetes mellitus; diabetes occurring during pregnancy.
PO Usually 1 to 2 g/day (range, 0.25 to 3 g) in 1 to 2 divided doses.For Diagnostic PurposesAdults
IV 1 g over 2 to 3 min.
May increase hypoglycemic effect.Beta-blockers, calcium channel blockers, cholestyramine, corticosteroids, diazoxide, estrogens, hydantoins, isoniazid, nicotinic acid, oral contraceptives, phenothiazines, rifampin, sympathomimetics, thiazide diuretics, thyroid agents, urinary alkalinizers
May decrease hypoglycemic effect.Charcoal
Charcoal can reduce the absorption of sulfonylureas; depending on the clinical situation, this will reduce their efficacy or toxicity.Digitalis glycosides
Coadministration may result in increased digitalis serum levels.Digoxin
May cause increased digoxin serum concentrations.Ethanol
May cause disulfiram-like reaction.
Drug may cause false-positive reaction for albumin with acidification-after-boiling test; no interference occurs with sulfosalicyclic acid test. Elevated LFTs and elevations in BUN and creatinine may occur.
Increased risk of cardiovascular mortality.
Allergic skin reactions; eczema; pruritus; erythema; urticaria; morbilliform or maculopapular eruptions; lichenoid reactions; porphyria; photosensitivity.
Nausea; epigastric fullness; heartburn.
Leukopenia; thrombocytopenia; aplastic anemia; agranulocytosis; hemolytic anemia; pancytopenia.
Hypoglycemia; SIADH with water retention and dilutional hyponatremia, especially in patients with CHF or hepatic cirrhosis.
Disulfiram-like reaction; weakness; paresthesia; fatigue; malaise; slight burning sensation along course of vein during IV injection; thrombophlebitis with thrombosis of injected vein.
Category C . Insulin is recommended to control elevated blood glucose levels during pregnancy.
Excreted into breast milk.
Safety and efficacy have not been established.
Particularly susceptible to hypoglycemic action. Hypoglycemia may be difficult to recognize in elderly.
Use drug with caution.
Use drug with caution.
Administration of drug with alcohol may induce facial flushing and breathlessness.
Patients treated for 5 to 8 yr with diet plus tolbutamide (1.5 g/day) had a rate of cardiovascular mortality approximately 2.5 times that of patients treated with diet alone.
Hypoglycemia including symptoms of the following: tingling of lips and tongue, nausea, lethargy, confusion, agitation, nervousness, tachycardia, sweating, tremor, hunger, convulsions, stupor, coma.
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