Acarbose is an alpha-glucosidase inhibitor drug that is used in the treatment of type 2 diabetes mellitus. It is normally given to patients who are non-insulin dependent where oral hypoglycemic agents or diet modification do not control their condition. The drug is commonly sold in China and Europe as Glocobay while in North America it is sold using the Precose brand name. Acarbose is an oligosaccharide that is normally formed by the process of fermenting a microorganism known as Actinoplanes utahensis. The drug is white and is soluble in water.
Acarbose acts by delaying the digestion of consumed carbohydrates, leading to a small increase in blood sugar levels. Acarbose minimizes the concentrations of glycosylated hemoglobin in patients with type 2 mellitus.
Acarbose does not enhance the secretion of insulin, which is in contrast to sulfonylureas. The drug’s antihyperglycemic action is because of competitive, reversible inhibition of pancreatic alpha-amylase and intestinal alpha-glucoside hydrolase enzymes that are membrane-bound. On one hand, the membrane-bound intestinal alpha-glucosidases hydrolyze trisaccharides, disaccharides, and oligosaccharides to glucose as well as other monosaccharides in the small intestine’s brush border. Through this enzyme inhibition in diabetic patients, postprandial hyperglycemia is lowered and glucose absorption is delayed.
Acarbose is a complex oligosaccharide that acts as a competitive, reversible inhibitor of pancreatic alpha-amylase and membrane-bound intestinal alpha-glucoside hydrolase. Pancreatic alpha-amylase hydrolyzes complex carbohydrates to oligosaccharides in the small intestine.
https://www.ncbi.nlm.nih.gov
Acarbose acts by preventing the digestion of complex carbohydrates; therefore, it should be administered orally at the start (with the first bite) of every meal, three times a day. It is important to note that patients should adhere to dietary instructions, regular testing of blood and urine glucose levels as well as regular exercise. However, Acarbose does not lead to hypoglycemia even when patients take it in a fasted state. Conversely, Acarbose is administered in combination with sulfonylurea drugs and insulin, thus can lead to low blood sugar, increasing the hypoglycemic potential of these agents.
It is noteworthy that Acarbose dosage should always be individualized based on both tolerance and effectiveness but not exceeding the maximum recommended dose of 100mg.t.i.d depending on the patient’s weight. In addition, if the prescribed diet is not adhered to, side effects in the intestines might increase. During the initiation of treatment, therapeutic response to Acarbose can be determined by one-hour postprandial plasma glucose as well as identifying the maximum effective dose for a specific patient. Glycosylated hemoglobin should then be measured at intervals of about three months,
The main aim of using Acarbose is to reduce glycosylated hemoglobin and postprandial plasma glucose levels to near normal by administering the lowest effective dose.
Before administering Acarbose to a patient, the doctor must ensure that the patient has ever had cirrhosis of the liver or any other liver disease, an inflammatory disease, or ketoacidosis. Acarbose is contraindicated in individuals that are known to exhibit hypersensitivity to the drug. In particular, patients with diabetic cirrhosis or ketoacidosis. The drug is also contraindicated in people with colonic ulceration, inflammatory bowel disease, and partial intestinal obstruction. Furthermore, Acarbose is contraindicated in individuals with intestinal disorders as well as conditions that may deteriorate due to increased levels of gas in the intestine.
Patients should inform the doctor or health worker that they are on Acarbose medication before having any surgery. Pregnant women should not also take the drug unless prescribed by a doctor.
Side effects normally develop during the first weeks of using the drug. Notably, they are primarily mild-to-moderate gastrointestinal effects.
One of the major side effects of Acarbose is the delivery of the remaining carbohydrate after degradation of some into glucose to the colon. Studies have revealed that 78% who use Acarbose experience flatulence and diarrhea as a result of digestion of the complex carbohydrates in the colon.
Most Acarbose effects are dose-related, therefore, it is advisable to begin with small dosage first and gradually increasing to the required amount of dose. The initial dosage is 25 mg t.i.d, which commonly given three times a day. After 4-8 weeks intervals, the maintenance dosage can be increased to 50mg t.i.d. The maximum dosage is 50mg t.i.d for patients who weigh less than 60kg while for those weighing above 60kg, it should be a maximum of 100 mg t.i.d. it is noteworthy that studies have indicated that gastrointestinal side effects can decrease from 50% to 15% over the intervals or even at the maintenance dosing stage.
A doctor or physician should be immediately called if a patient suffers from hyperglycemia. The patient can also eat food comprising of monosaccharides such as gel or glucose tablet.
The doctor should be informed immediately if a patient is experiencing fevers, unusual stress, and illness when taking Acarbose since such events typically lead to a change of blood sugar levels thus affecting the required dosage.
Studies have revealed that Acarbose can help patients with diabetes to lose weight.
Severe Acarbose side effects include severe itching, constipation, unusual bleeding, and yellowing of eyes and skin.
https://www.rxlist.com/precose-side-effects-drug-center.htm
Acarbose, a complex oligosaccharide isolated from Actinoplanes, is reportedly
useful as an adjuvant therapy in diabetes. By inhibiting alpha-glucosidase,
acarbose delays carbohydrate metabolism in the gastrointestinal tract and modulates
changes in food induced blood sugar levels.
antipsychotic: 5HT antagonist, dopamine antagonist, H1-antihistamine, alpha adrenergic blocker
A reversible alpha-glucosidase inhibitorAcarbose is used as a reversible alfa-glucosidase inhibitor. It acts as an anti-diabetic drug, which finds useful application to treat type 2 diabetes mellitus and prediabetes. It is also employed for Hepatitis. It also acts as a beta glucosidase inhibitor, antihyperlipidaemia and antiobesity.
Acarbose is pseudo-oligosaccharide with a terminal C7-cyclitol patented in 1975 by Bayer. Acarbose is a component of the amylostatin complex produced by a species of Actinoplanes and Streptomyces. Acarbose acts as a potent inhibitor of alpha-glucosidases and saccharases. Since 1990, acarbose has been used therapeutically for the treatment of type 2 diabetes.
ChEBI: Acarbose is a tetrasaccharide derivative consisting of a dideoxy-4-{[4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl C7 cyclitol moiety [called valienol (or valienamine)] linked via nitrogen to isomaltotriose. It has a role as an EC 3.2.1.20 (alpha-glucosidase) inhibitor, an EC 3.2.1.1 (alpha-amylase) inhibitor, a hypoglycemic agent and a geroprotector. It is a conjugate base of an acarbose(1+).
The title compound was obtained from a cultural broth of fermenting a
microorganism of family Actinoplanaceae in particular of strain genus
Actinoplanes, according to DT-OS (German Published Specification) No.
2,347,782.
50 g of cation exchange resin (Lewatit S 1040W) in the H+ form and 30 g an
anion exchanger (Lewatit M 600) in OH form were added to 300 ml of a
culture broth with mycelium content of 25% and an inhibitor content of 50
SIU/ml in solution. The mixture was stirred at room temperature for 50
minutes. The solution, containing a sieving nozzle with 0.1 mm slits. For testing, a sample of filtered broth was centrifuged and was examined for
saccharase inhibitor in the supernatant liquor. The solution contained 2.5
SIU/ml, that is to say 5%, of starting activity. This procedure improved the
yield of the aminosugar from 20% in the procedure known from DT-OS
(German Published Specification) No. 2,347,782, to 50-60%. It has now found
that cation exchangers based on styrene, divinylbenzene and
methoxymethylmethacrylamide, oxyethyl(meth)acrylic acid amide (ester),
dimethylaminoethyl(meth)acrylic acid amide (ester) or oxypropyl(meth)acrylic
acid amide(ester) are preferred in industrial separation procedure of acarbose.
This exchanger gave a very sharp separation of the individual homologues and
impurities. And it has now found the new biosynthesis of acarbose by using of
gen engineering methods.
Precose (Bayer);Glucobay.
World Health Organization (WHO)
Acarbose, ana-glucosidase inhibitor, is used as an adjunctive
therapy in the control of postprandial hyperglycaemia in non-insulin-dependent
diabetes mellitus. Use of two or more hypoglycaemic drugs is not recommended.
Acarbose is a naturally occurring oligosaccharide,which is obtained from the microorganism Actinoplanes utahensis. It is a white to off-white powder that is soluble in water and has a pKa of 5.1. As one mightexpect, its affinity for α-glucosidase is based on it being apolysaccharide that the enzyme attempts to hydrolyze. Thisallows acarbose to act as a competitive inhibitor, which inturn reduces the intestinal absorption of starch, dextrin, anddissacharides.
It is sold as 25-, 50-, and 100-mg tablets (Precose,generics) dosed with the first bite of each meal, up to t.i.d. Acarbose potently inhibits the glucoamylase activity of MGAM α-glucosidases and the sucrase activity of α-glucosidases, where as isomaltase activity is at most moderately inhibited at concentrations in the range of those in theintestinal lumen upon oral dosing, and trehalase and lactaseare not significantly inhibited. Some inhibition of pancreaticα-amylases may also contribute to the clinical effects.
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Modified tetrasaccharide that acts as a reversible α -glucosidase inhibitor.
Based on the structure of acarbose, it should come as nosurprise that little intact acarbose reaches the systemic circulation;instead, acarbose is extensively biotransformed by the actionof microbes and digestive enzymes in the gut. Only about35% of the radioactivity in a dose of 14C-labeled acarbose administeredorally to men was excreted in the urine, appearingas several metabolites, some of which are phase II conversionproducts of 4-methylpyrogallol (O-methyl, O-sulfate, orO-glucuronide conjugates); the methylpyrogallol fragmentarises from the terminal valienamine pseudosugar. That thesebiotransformation products are mostly formed in the gut isshown by the fact that nearly 90% of an intravenously administereddose of acarbose is excreted intact in urine.
Low toxicity by ingestion,subcutaneous, and intravenous routes. Human systemiceffects: liver function impaired. When heated todecomposition it emits toxic vapors of NOx.
Veterinary Drugs and Treatments
May be useful for mild reductions
in blood glucose concentrations
(250 – 350 mg/dl range) in dogs and cats with non-insulin-dependent
diabetes mellitus and as adjunctive treatment
of insulin dependent
diabetes mellitus.
Potentially hazardous interactions with other drugs
Antibacterials: hypoglycaemic effect possibly
enhanced and increased gastrointestinal side effects
with neomycin.
Lipid lowering agents: hypoglycaemic effect possibly
enhanced by colestyramine.
Oral bioavailability is 1-2%. After oral administration of
the 14C-labelled substance, on average, 35% of the total
radioactivity was excreted by the kidneys within 96 hours.
The proportion of drug excreted in the urine was 1.7% of
the administered dose. 50% of the activity was eliminated
within 96 hours in the faeces.
