Alpha-Glucosidase Inhibitors: Mechanism and Side Effects

This document provides an overview of alpha-glucosidase inhibitors, a class of anti-diabetic drugs that reduce blood glucose levels by inhibiting the breakdown of complex carbohydrates in the small intestine. The document discusses their mode of action, side effects, contraindications, and bibliography for diabetes management.

Alpha- glucosidase inhibitors
Pharmacodynamics is the science in which we study the effect of drug on the organisms. It
describes the relationship between the drug concentration towards the site of action and its
effects like biochemical and physiological actions. The action of the drug at the site is
determined by that drug binding with the receptor. The receptors on cardiac muscle which
affects the rate of contraction, the opiate receptor i.e. receptors of neurons reduce the
intensity of pain or also the receptors within the bacteria which alters the maintenance of the
cell wall.
Alpha- glucosidase inhibitors are the class of anti-diabetic drugs also known as starch
blockers that reduces the blood glucose levels in a diabetic patient (Bischoff, 2017). They are
a group of reversible and poorly absorbed inhibitors of small intestine tract where absorption
occurs. It prevents the breakdown of complex carbohydrates into simpler form i.e. glucose. It
stops the action of enzymes which acts to degrade the carbohydrates present in the small
intestine. As per its name it does not affect the insulin secretion or sensitivity. It slows down
the digestion of carbohydrates present in starchy foods.
Previously alpha glucosidase was used to be isolated from medicinal plants and
microorganisms. From the various research it has been revealed that alpha glucosidase
enzyme from rat intestine, mouse intestine and from yeast has been used for pharmacological
screenings. For the enzyme inhibition assays coffee glucosidase, intestinal isomaltase of rat,
alpha glucosidase type 4 of Bacillus stearothermophilus were used as the source of enzymes.
Acarbose, Genistein, quercitrin have been used as the positive control in screenings.
Alpha glucosidase is mainly recommended as the first line of drug for the patient with type 2
diabetes when diet and exercise along with the combination of antidiabetic and insulin cannot
decrease the post prandial blood glucose (Maffioli, 2012).
Mode of actions of Alpha- Glucosidase inhibitors:
It is normally taken with the meal usually to treat postprandial hyperglycaemia, a problem
faced by patient suffering from type 2 diabetes (S, 2014). This drug slows down the
absorption of carbohydrate by inhibiting enzymes of the small intestine which helps in
carbohydrate metabolism. In spite this drug gets partially absorbed in the blood stream its
mode of action happens entirely in the lumen. There are various classes of diabetes medicine
which work differently to control high blood sugar. Metfromin helps to decrease glucose
level in liver. Sulfonylureas and meglitinides helps in stimulating the pancreas resulting in
release of more insulin. Similarly, thiazolidinediones helps to increase fat and muscles cell
sensitivity to release insulin.
Alpha glucosidase inhibitors act on two types of enzymes in the small intestines.
1. Acarbose and Miglitol
As we know that alpha glucosidase present in the intestine metabolizes the carbohydrates so
that they get dissolved into the blood stream. However, the alpha glucosidase inhibitors
prevent the immediate breakdown of carbohydrates into monosaccharides or sugars and
eventually slowing down their absorption into the blood stream.

2.Pancreatic enzymes
Once a person takes his meal the enzymes present in the pancreas metabolizes the
carbohydrates so that they get absorbed into the blood stream. But acarbose blocks the
pancreatic enzyme i.e. alpha amylase by inhibiting the breakdown of starch and there by
slowing down its absorption into the blood stream.
Side effects of Alpha-glucosidase inhibitor:
As it is evident that alpha glucosidase inhibitors help in treatment with the patient suffering
from postprandial hyperglycaemia, it has its side effects too. These are listed below:
Gastrointestinal effects
These are one of the most common side effects of glucosidase inhibitors. These inhibitors
affect almost 50% of people causing gastrointestinal disorders. It causes excessive gas
production because of the fermentation of carbohydrates that has been unabsorbed. As the
drug prevents the breakdown of carbohydrates in the small intestine which results in reaching
more carbohydrates into the large intestine. The carbohydrates into the large intestine gets
converted into gas by the action of bacteria present over there. This also results in nausea,
diarrhoea, abdominal cramps, flatulence etc. Because of these side-effects most of the
patients discontinue these drugs. The best way to minimize these side effects is by taking
small dose initially and then by gradually increasing the doses.
Increase in Liver enzymes (Acarbose only)
In some cases, it has been observed that the patient weighing less than 60 kg were having
elevated liver enzymes. This was mainly due to the intake of higher doses of acarbose. Due to
this the dosage of acarbose was restricted to 50mg for the patient weighing less than 60.
Hypoglycaemia
Due to the unique mechanism of action of this drug it is often combined with other diabetic
drugs. Alpha glucosidase inhibitor alone does not cause low blood glucose level. When they
are combined with another diabetic drug hypoglycaemia occurs. This drug slows down the
mechanism of carbohydrate absorption, it cannot help in treating hypoglycaemia is by intake
of pure glucose either in the form of gel or tablet. Direct intake of table sugar does not help as
alpha glucosidase inhibitors blocks sucrose metabolism.
Contraindication of Alpha-glucosidase inhibitor
Alpha glucosidase inhibitors should be avoided by the patient who are suffering from
digestion or absorption disorders and also the patients whose conditions may deteriorate by
the increase of gas formation in the intestine (Hypoglycemics, Alpha glucosidase inhibitors
review, 2010).
Acarbose and miglitol should be avoided in case the patient is suffering from liver cirrhosis,
colon ulcer, colon ulcer, irritable bowel syndrome or inflammatory bowel disease, patients
predisposed to intestinal obstruction and partial intestinal obstruction.

Miglitol and Acarbose should be avoided by the patient having kidney diseases as these drugs
elevates the blood levels.
Bibliography
Bischoff, H. (2017). The mechanism of alpha-glucosidase inhibition in the management of
diabetes. Pubmed.
Hypoglycemics, Alpha glucosidase inhibitors review. (2010). Provider Synergies, L.L.C., 1-
6.
Maffioli, G. D. (2012). Alpha glucosidase inhibitors and their use in clinical practice. NCBI,
899-906.
S, K. (2014). Alpha glucosidase inhibitors. NCBI.