Drug Approvals
(British Approved Name, US Adopted Name, rINN)
Pharmacopoeias. In British, Japan, and US.
BP 2008 (Tolazamide). A white or almost white, odourless or almost odourless, crystalline powder. Very slightly soluble in water slightly soluble in alcohol soluble in acetone freely soluble in chloroform.
The United States Pharmacopeia 31, 2008 (Tolazamide). A white or off-white crystalline powder, odourless or having a slight odour. Very slightly soluble in water slightly soluble in alcohol soluble in acetone freely soluble in chloroform.
Adverse Effects, Treatment, and Precautions
As for sulfonylureas in general.
Porphyria. Tolazamide has been associated with acute attacks of porphyria and is considered unsafe in porphyric patients.
Interactions
As for sulfonylureas in general.
Pharmacokinetics
Tolazamide is slowly absorbed from the gastrointestinal tract, peak plasma concentrations occurring 4 to 8 hours after a dose by mouth, and is extensively bound to plasma proteins. It has a half-life of about 7 hours. It is metabolised in the liver to metabolites with some hypoglycaemic activity. About 85% of an oral dose is excreted in the urine, chiefly as metabolites.
Uses and Administration
Tolazamide is a sulfonylurea antidiabetic. It is given orally in the treatment of type 2 diabetes mellitus and has a duration of action of at least 10 hours and sometimes up to 20 hours. The usual initial dose is 100 to 250 mg daily given as a single dose with breakfast. Dosage may be increased if necessary at weekly intervals by 100 to 250 mg, usually to a maximum of 1 g daily no further benefit is likely to be gained with higher doses. Doses of more than 500 mg daily may be given in divided doses.
Preparations
British Pharmacopoeia 2008: Tolazamide Tablets
The United States Pharmacopeia 31, 2008: Tolazamide Tablets
Proprietary Preparations
USA: Tolinase