Glipizide metabolites

Glipizide and glyburide are extensively metabolized (Fig. 32.5) to less active or inactive metabolites. Glipizide metabolites are excreted primarily in the urine, whereas glyburide s metabolites are excreted equally in the urine and bile. 

Glipizide has its maximal effect after 1 hour but its duration of action can extend over 24 hours. It is metabolized in the liver to inactive metabolites. 

Glyburide (DiaBeta, Micronase, Glynase), also known as glibenclamide, is approximately 150 times as potent as tolbutamide on a molar basis and twice as potent as glipizide (discussed later). Glyburide is completely metabolized in the liver to two weakly active metabolites before excretion in the urine. Its average duration of action is 24 hours. 

Glipizide (Glucotwl) is similar to glyburide, but it is metabolized by the liver to two inactive metabolites these metabolites and glipizide are renally excreted. 

Geriatric Considerations - Summary Glipizide is primarily metabolized in the liver to inactive metabolites, therefore may be safer in older adults. Elimination half-life in older adults is not increased as compared to younger adults. Hypoglycemia risk may be increased with use of the long-acting formulation of glipizide. 

Glipizide (Y) Glucotrol 5, 10 5 2.5-5 5 40 Up to 20 hours lites that are renally cxaeted Metabolized in liver to inacte metabolites... 

Metabolism/ elimination Acetohexamide, chlorpropamide, tolazamide, glyburide glimepiride weakly active metabolites. Glipizide, tolbutamide inactive metabolites. Inactive metabolites Predominantly inactive metabolites Excreted unchanged in urine Extensively metabolized in liver to metabolites Acarbose inactive metabolites. Miglitol excreted unchanged in urine. 

Glipizide Two hydroxycyclohexyl derivatives A-(2)-acetylaminoethylphenylsulphonyl-A, -cyclohexylurea (i) Two unidentified metabolites... 

Glipizide is absorbed rapidly, is bound to plasma protein to the extent of 92 to 99%, and is metabolized to inactive metabolites, which are excreted in the urine. 

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