Acarbose excretion

Metabolism - Acarbose is metabolized exclusively within the Gl tract, principally by intestinal bacteria, but also by digestive enzymes. A fraction of these metabolites (about 34% of the dose) was absorbed and subsequently excreted in the urine. 

Excretion - The fraction of acarbose that is absorbed as intact drug is almost completely excreted by the kidneys. When acarbose was given IV, 89% of the dose was recovered in the urine as active drug within 48 hours. In contrast, less than 2% of an oral dose was recovered in the urine as active (ie, parent compound and active metabolite) drug. The plasma elimination half-life of acarbose activity is about 2 hours in healthy volunteers. 

Acarbose Precose) is an ohgosaccharide derivative that has a higher affinity for the a- glucosidase enzymes than do other dietary oUgosaccharides. Systemic absorption of acarbose is very low ( 2%), with most being broken down in the intestine to several metabolites. About half of the orally administered acarbose is excreted unchanged in the feces, while the remainder, some of which is systemically absorbed, is renally excreted. Acarbose may be associated with hepatotoxicity in rare instances. 

Miglitol (Glyset) is another a-glucosidase inhibitor, but in contrast to acarbose, mightol is systemically absorbed prior to its activity in the small intestine. It also appears to inhibit the enzymes sucrase and maltase to a greater extent than does acarbose. It does not undergo metabolism and is renally excreted unchanged. 

Acarbose is not well absorbed and is mostly excreted in the feces. Miglitol is well absorbed from the gut and is almost completely excreted unchanged in the urine (10). 

The different mechanisms of action of the various classes of hypoglycemic drugs makes combined therapy feasible the sulfonylureas and meglitinides stimulate insulin production by different mechanisms, the biguanides reduce glucose production by the liver and excretion from the liver, acarbose reduces the absorption of glucose from the gut, and the thiazolidinediones reduce insulin resistance in fat. It is not necessary to wait until the maximal dose of... 

Miglitol (73) is the most potent in a series of derivatives of the natural product moranoline (1-deoxynojirimycin) (72), which appear to closely mimic glucose (71), and which inhibit a-glucoamylase and sucrase [334]. Unlike acarbose, miglitol is almost completely absorbed, possibly via the glucose transporter mechanism, and is excreted through the kidney, a... 

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. 

The faecal excretion of acarbose and component-II was almost complete within 24 h of administration of a single dose of 300 mg orally and amounted... 

Several other long-term effects of acarbose were explored in healthy men by Couet et al. (1988). There was an increase in faecal nitrogen excretion, while nitrogen balance decreased. Acarbose also increased the faecal excretion of starch, fat, iron and chromium. Plasma vitamin A decreased following acarbose treatment, while vitamin B6 increased. 

Pharmacokinetics. The mechanism of action of a-glucosidase inhibitors is limited to the luminal side of the intestine. Some metabolites of acarbose are systemically absorbed and renally excreted, whereas the majority of miglitol is absorbed and renally excreted unchanged. 

A study in 6 healthy subjects found that acarbose 50 to 100 mg three times daily reduced the maximum serum levels and the AUC0.9 of metformin 1 g by about 35%, but the 24-hour urinary excretion was unchanged." ... 

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