Adult: Initially, 100-250 mg daily as a single dose in the morning. Increase at wkly intervals by 100-250 mg if necessary. Maintenance: 250-500 mg daily. Doses >500 mg daily can be given in divided doses. Max: 1000 mg daily. Elderly: Initial: 100 mg daily in the morning.
Special Patient Group
Malnourished patient: Initial: 100 mg daily in the morning.
Renal Impairment
Conservative initial and maintenance dosing.
Hepatic Impairment
Conservative initial and maintenance dosing.
Administration
Should be taken with food.
Contraindications
Hypersensitivity to tolazamide, sulfonylureas. Sole therapy in type 1 DM, diabetic ketoacidosis w/ or w/o coma, or other acute complications (e.g. major surgery, severe infection or trauma), uraemia.
Special Precautions
Patient w/ history of hepatic porphyria, G6PD deficiency. Elderly, debilitated and malnourished patients. Renal or hepatic impairment. Pregnancy and lactation.
Monitor blood glucose, glycosylated Hb level, signs and symptoms of hypoglycaemia.
Overdosage
Symptoms: Hypoglycaemia. Management: Mild hypoglycaemic symptoms w/o loss of consciousness or neurologic findings may be treated w/ oral glucose and adjustments in drug dosage and/or meal patterns. For hypoglycaemic coma, admin rapid IV inj of concentrated (50%) glucose soln followed by continuous infusion of a more dilute (10%) glucose soln.
Drug Interactions
Increased plasma concentration w/ certain antifungals (e.g. miconazole, fluconazole). NSAIDs and other highly protein-bound drugs (e.g. chloramphenicol, salicylates, sulfonamides, probenecid, coumarins, MAOIs, β-blockers) may potentiate hypoglycaemic action of tolazamide. Diminished therapeutic effect w/ thiazides, other diuretics, phenothiazines, corticosteroids, thyroid products, oestrogens, OC, phenytoin, nicotinic acid, sympathomimetics, Ca channel blockers and isoniazid.
Food Interaction
May cause disulfiram-like reactions w/ alcohol.
Action
Description: Tolazamide, a sulfonylurea antidiabetic agents that lowers blood glucose by stimulating the secretion of endogenous insulin from pancreatic β-cells. Onset: 20 min. Duration: 10-24 hr. Pharmacokinetics: Absorption: Slowly but well absorbed from the GI tract. Time to peak plasma concentration: 4-8 hr. Distribution: Plasma protein binding: 94%. Metabolism: Extensively hepatic to 5 metabolites. Excretion: Via urine (approx 85%) and faeces (7%). Half-life: Approx 7 hr.
Chemical Structure
Tolazamide Source: National Center for Biotechnology Information. PubChem Database. Tolazamide, CID=5503, https://pubchem.ncbi.nlm.nih.gov/compound/Tolazamide (accessed on Jan. 23, 2020)
Anon. Tolazamide. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 18/08/2014.Buckingham R (ed). Tolazamide. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 18/08/2014.McEvoy GK, Snow EK, Miller J et al (eds). Tolazamide. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 18/08/2014.Tolinase Tablet (Pharmacia and Upjohn Company). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 18/08/2014.