Drugs Information Online
Drugs and diseases reference index

Drugs and diseases reference index

Drugs A-Z List

Diseases & Conditions A-Z List

Herbs & Supplements

Medical Dictionary

Full Article

Popular Drugs

Popular Diseases & Conditions

Drugs reference index «Tolazamide»


Pronunciation: (tole-AZE-uh-mid)Class: Sulfonylurea

Trade Names:Tolazamide- Tablets 100 mg- Tablets 250 mg- Tablets 500 mg


Decreases blood glucose by stimulating release of insulin from pancreas.



Tolazamide T max is 3 to 4 h. The drug is well absorbed from the GI tract.


There are 5 major metabolites ranging in hypoglycemic activity from 0% to 70%.


Tolazamide t ½ is 7 h. Tolazamide is excreted principally in the urine (85%), and 7% in feces over a 5-day period.


Onset of action of tolazamide is 4 to 6 h.


Time to peak effect of tolazamide is 4 to 6 h.


Duration of action is 10 h.

Indications and Usage

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.

Unlabeled Uses

Temporary adjunct to insulin therapy in selected patients with non–insulin-dependent diabetes mellitus to improve diabetic control.


Hypersensitivity to sulfonylureas; diabetes complicated by ketoacidosis, with or without coma; sole therapy of insulin-dependent (type 1) diabetes mellitus; gestational diabetes.

Dosage and Administration


PO 100 to 250 mg/day with breakfast or first main meal. If fasting blood sugar (FBS) is less than 200 mg/dL, initial dose is 100 mg/day or if FBS is greater than 200 mg/dL, initial dose is 250 mg/day. In malnourished, underweight, elderly patients use 100 mg/day. May adjust dose by 100 to 250 mg/wk as needed to a maximum of 1000 mg/day. If more than 500 mg/day is required, give in divided doses twice daily. Doses greater than 1 g/day are not likely to improve control.

Maintenance dose

PO Usual dose is 100 to 1000 mg/day with the average 250 to 500 mg/day. Following initiation of therapy, dosage adjustment is made in increments of 100 to 250 mg at weekly intervals based on patient's blood glucose response.

Drug Interactions

Androgens, anticoagulants, azole antifungals, chloramphenicol, clofibrate, fenfluramine, fluconazole, gemfibrozil, histamine H 2 antagonists, magnesium salts, methyldopa, MAOIs, phenylbutazone, probenecid, salicylates, sulfinpyrazone, sulfonamides, tricyclic antidepressants, urinary acidifiers

Increased 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

Decreased hypoglycemic effect.


Charcoal can reduce the absorption; depending on clinical situation, this will reduce sulfonylureas efficacy or toxicity.

Digitalis glycosides

Coadministration may result in increased digitalis serum levels.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Increased risk of cardiovascular mortality.


Dizziness; vertigo.


Allergic skin reactions; eczema; pruritus; erythema; urticaria; morbilliform or maculopapular eruptions; lichenoid reactions.


Nausea; epigastric fullness; heartburn; cholestatic jaundice.


Mild diuresis.


Leukopenia; thrombocytopenia; aplastic anemia; agranulocytosis; hemolytic anemia; pancytopenia; hepatic porphyria.




Disulfiram-like reaction; weakness; paresthesia; fatigue; malaise.



Category C .




Safety and efficacy not established.


Elderly and debilitated patients are particularly susceptible to hypoglycemic action of sulfonylureas.

Renal Function

Use drug with caution and monitor renal function frequently.

Hepatic Function

Use drug with caution and monitor liver function frequently.


Tolazamide may produce severe hypoglycemia, which may be more difficult to recognize in elderly or in patients receiving beta-blockers.

Disulfiram-like syndrome

Administration with alcohol may include facial flushing reaction and occasional breathlessness. This reaction has been reported more commonly with other sulfonylureas.


Hyperglycemia is major risk factor in development of diabetic complications. Measurement of glycosylated hemoglobin and self-monitoring of blood glucose are useful.

Loss of blood glucose control

Stress (including fever, trauma, infection, or surgery) or secondary failure (wherein drug's effectiveness in lowering blood glucose diminishes over time) may precipitate loss of blood glucose control.



Hypoglycemia including symptoms of the following: tingling of lips and tongue, nausea, lethargy, confusion, agitation, nervousness, tachycardia, sweating, tremor, hunger, convulsions, stupor, coma.

Patient Information

  • Teach signs and symptoms of hypoglycemia (eg, profuse sweating, excessive hunger, weakness, dizziness, tremor, tachycardia, anxiety, numbness of extremities) and of hyperglycemia (eg, excessive thirst or urination, urinary glucose or ketones, fever, sore throat, unusual bleeding or rash). Remind patient to keep source of quick-acting sugar available at all times.
  • When adjusting the dose, tell patient to check urine for ketones and blood for glucose 3 times a day; 1 to 2 times a day after stable control is established. Tell patient to notify health care provider if planning surgery or experiencing vomiting, injury, infection, or fever.
  • Demonstrate correct technique for performing blood glucose and urine glucose and ketone tests, and ensure correct return demonstrations.
  • Tell patient to report repeated abnormal glucose or ketone results to health care provider.
  • Emphasize importance of continuing diet restrictions and exercise regimen.
  • Caution about disulfiram-like syndrome (eg, facial flushing, abdominal cramping, nausea) when consuming alcohol. Advise patient to avoid alcohol.
  • Inform patient that therapy will not cure disease.

Copyright © 2009 Wolters Kluwer Health.

  • Tolazamide MedFacts Consumer Leaflet (Wolters Kluwer)
  • Tolazamide Prescribing Information (FDA)
  • Tolazamide Detailed Consumer Information (PDR)
  • Tolinase Prescribing Information (FDA)
  • tolazamide Concise Consumer Information (Cerner Multum)
  • tolazamide Advanced Consumer (Micromedex) - Includes Dosage Information

See Also...