Icodextrin
Encyclopedia
Icodextrin is a colloid
osmotic agent, derived from maltodextrin
, used in form of an aqueous solution for peritoneal dialysis
under the trade name Extraneal, and after gynecological laparoscopic surgery for the reduction of post-surgical adhesion
s (fibrous bands that form between tissues and organs) under the trade name Adept.
-derived, branched, water-soluble glucose
polymer
linked by α-(1→4) and less than 10% α-(1→6) glycosidic bond
s, making it a type of dextrin
. Its weight-average molecular weight is between 13,000 and 19,000 Daltons and its number-average molecular weight between 5,000 and 6,500 Daltons. The substance is a white to off-white solid, and the solution is clear and colourless to pale yellow.
for three to four days, separating tissues and thus reducing adhesion between them when fibrin
is formed after a surgery. In other words, the tissues are kept from gluing together.
When used for peritoneal dialysis, the icodextrin solution absorbs waste products from the blood, and is removed from the peritoneum after a few hours together with the waste.
s. There it is broken down into oligosaccharide
s by the enzyme alpha-amylase
. In patients with intact kidney function, both icodextrin and its fragments are excreted via the kidney by glomerular filtration.
or isomaltose
intolerance, glycogen storage disease
, or severe lactic acidosis
.
, respiratory infection, hypertension
(high blood pressure), rash
es, and headache. Of these side effects, only hypertension and rashes occurred significantly more often than under glucose solution; the other events seem to be related to peritoneal dialysis in general.
Colloid
A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...
osmotic agent, derived from maltodextrin
Maltodextrin
Maltodextrin is a polysaccharide that is used as a food additive. It is produced from starch by partial hydrolysis and is usually found as a creamy-white hygroscopic spraydried powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might be either moderately sweet or...
, used in form of an aqueous solution for peritoneal dialysis
Peritoneal dialysis
Peritoneal dialysis is a treatment for patients with severe chronic kidney disease. The process uses the patient's peritoneum in the abdomen as a membrane across which fluids and dissolved substances are exchanged from the blood...
under the trade name Extraneal, and after gynecological laparoscopic surgery for the reduction of post-surgical adhesion
Adhesion (medicine)
Adhesions are fibrous bands that form between tissues and organs, often as a result of injury during surgery. They may be thought of as internal scar tissue that connect tissues not normally connected.-Pathophysiology:...
s (fibrous bands that form between tissues and organs) under the trade name Adept.
Physical and chemical properties
Icodextrin is a starchStarch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
-derived, branched, water-soluble glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
linked by α-(1→4) and less than 10% α-(1→6) glycosidic bond
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....
s, making it a type of dextrin
Dextrin
Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen. Dextrins are mixtures of polymers of D-glucose units linked by α- or α- glycosidic bonds....
. Its weight-average molecular weight is between 13,000 and 19,000 Daltons and its number-average molecular weight between 5,000 and 6,500 Daltons. The substance is a white to off-white solid, and the solution is clear and colourless to pale yellow.
Mechanism of action
The osmotic activity of icodextrin keeps the solution inside the peritoneumPeritoneum
The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...
for three to four days, separating tissues and thus reducing adhesion between them when fibrin
Fibrin
Fibrin is a fibrous, non-globular protein involved in the clotting of blood. It is a fibrillar protein that is polymerised to form a "mesh" that forms a hemostatic plug or clot over a wound site....
is formed after a surgery. In other words, the tissues are kept from gluing together.
When used for peritoneal dialysis, the icodextrin solution absorbs waste products from the blood, and is removed from the peritoneum after a few hours together with the waste.
Pharmacokinetics
Icodextrin is not significantly metabolised inside the peritoneum. Instead, it is absorbed slowly (40% after 12 hours) into the bloodstream via the lymph vesselLymph vessel
In anatomy, lymph vessels are thin walled, valved structures that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and deep to that have a thin layer of smooth muscles, and adventitia that bind...
s. There it is broken down into oligosaccharide
Oligosaccharide
An oligosaccharide is a saccharide polymer containing a small number of component sugars, also known as simple sugars...
s by the enzyme alpha-amylase
Alpha-Amylase
α-Amylase is an enzyme that hydrolyses alpha-bonds of large alpha-linked polysaccharides such as starch and glycogen, yielding glucose and maltose. It is the major form of amylase found in humans and other mammals...
. In patients with intact kidney function, both icodextrin and its fragments are excreted via the kidney by glomerular filtration.
Contraindications
Icodextrin is contraindicated in patients with cornstarch allergy, maltoseMaltose
Maltose , or malt sugar, is a disaccharide formed from two units of glucose joined with an αbond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α bond. Maltose is the second member of an important biochemical series of glucose chains....
or isomaltose
Isomaltose
Isomaltose is a disaccharide similar to maltose, but with a α--linkage instead of the α--linkage. It is a reducing sugar. Both of the sugars are glucose and pyranoses...
intolerance, glycogen storage disease
Glycogen storage disease
Glycogen storage disease is the result of defects in the processing of glycogen synthesis or breakdown within muscles, liver, and other cell types. GSD has two classes of cause: genetic and acquired. Genetic GSD is caused by any inborn error of metabolism involved in these processes...
, or severe lactic acidosis
Lactic acidosis
Lactic acidosis is a physiological condition characterized by low pH in body tissues and blood accompanied by the buildup of lactate especially D-lactate, and is considered a distinct form of metabolic acidosis. The condition typically occurs when cells receive too little oxygen , for example...
.
Adverse effects
Adverse effects include peritonitisPeritonitis
Peritonitis is an inflammation of the peritoneum, the serous membrane that lines part of the abdominal cavity and viscera. Peritonitis may be localised or generalised, and may result from infection or from a non-infectious process.-Abdominal pain and tenderness:The main manifestations of...
, respiratory infection, hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
(high blood pressure), rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
es, and headache. Of these side effects, only hypertension and rashes occurred significantly more often than under glucose solution; the other events seem to be related to peritoneal dialysis in general.