DESCRIPTION
An inhibitor of alpha glucosidase that retards the digestion and absorption of carbohydrates in the small intestine and hence reduces the increase in blood-glucose concentrations after a carbohydrate load. It is given orally to non-insulin dependent diabetes mellitus patients where diet modification or oral hypoglycemic agents do not control their condition.
CATEGORIES
Antidiabetic Agents
CHEMICAL FORMULA
C25H43NO18
COMPOSITION
Acarbose 50mg
INDICATION
For treatment and management of diabetes type II (used in combination therapy as a second or third line agent)
PHARMACODYNAMICS
Used to reduce blood gluose in patients with type 2 diabetes. Acarbose is a complex oligosaccharide that delays the digestion of ingested carbohydrates, thereby resulting in a smaller rise in blood glucose concentration following meals. Acarbose binds to and inhibits alpha amylase and alpha-gluocside hydrolases. In diabetic patients, this enzyme inhibition results in a delayed glucose absorption and a lowering of postprandial hyperglycemia.
MECHANISM
Acarbose reversibly bind to pancreatic alpha-amylase and membrane-bound intestinal alpha-glucoside hydrolases. These enzymes inhibit hydrolysis of complex starches to oligosaccharides in the lumen of the small intestine and hydrolysis of oligosaccharides, trisaccharides, and disaccharides to glucose and other monosaccharides in the brush border of the small intestine.
ABSORPTION
Extremely low bioavailability. Less than 2% of an oral dose of acarbose was absorbed as active drug. Peak plasma concentrations of the active drug were achieved 1 hour after dosing. Drug accumulation does not occur with multiple doses.
METABOLISM
Acarbose is only metabolized within the gastrointestinal tract by intestinal bacteria and also digestive enzymes to a lesser extent. 4-methylpyrogallol derivatives (sulfate, methyl, and glucuronide conjugates) are the major metabolites. One metabolite (formed by cleavage of a glucose molecule from acarbose) also has alpha-glucosidase inhibitory activity.
ELIMINATION
The fraction of acarbose that is absorbed as intact drug is almost completely excreted by the kidneys. A fraction of the metabolites (approximately 34% of the dose) was absorbed and subsequently excreted in the urine. The active metabolite is excreted into the urine and accounts for less than 2% of the total administered dose. When given intravenously, 89% of the dose was excreted into the urine as the active drug. When given orally, less than 2% of the oral dose was recovered into the urine as active (parent compound and active metabolite) drug.
HALF LIFE
Healthy volunteers = 2 hours
TOXICITY
Gastrointestinal symptoms are the most common reactions to acarbose.
FOOD INTERACTIONS
Take with food, at beginning of each meal.
SIDE EFFECTS
Belly pain, gas, loose stools (diarrhea), lightheadedness, sweating, nervousness or irritability