Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties
Pharmacotherapeutic group: Blood substitutes and perfusion solutions, IV solutions, solu- tions for parenteral nutrition, amino acids.
ATC code: B05B A01
Mechanism of action
The aim of parenteral nutrition is the supply of all nutrients necessary for the growth, maintenance and regeneration of body tissues etc.


Amino acids are of special importance as they are partly essential for protein synthesis. In- travenously administered amino acids are incorporated in the respective intravascular and in- tracellular amino acid pools. Both endogenous and exogenous amino acids serve as substrate for the synthesis of functional and structural proteins.


To prevent the metabolisation of amino acids for energy production, and also to fuel the oth- er energy-consuming processes in the organism, simultaneous non-protein energy supply (in the form of carbohydrates or fats) is necessary.

Pharmacokinetic Properties

5.2   Pharmacokinetic properties
Absorption
Because this medicinal product is infused intravenously, the bioavailability of the amino ac- ids contained in the solution is 100 %.


Distribution
Amino acids are incorporated in a variety of proteins in different tissues of the body. In ad- dition, each amino acid is present as free amino acid in the blood and inside cells.
The composition of the amino acid solution is based upon the results of clinical investiga- tions of the metabolism of intravenously administered amino acids. The quantities of the amino acids contained in the solution have been chosen so that a homogenous increase in the concentrations of all plasma amino acids is achieved. The physiological ratios of plasma amino acids, i. e. amino acid homeostasis, are thus maintained during infusion of the medic- inal product.
Normal foetal growth and development depend on a continuous supply of amino acids from the mother to the foetus. The placenta is responsible for the transfer of amino acids between the two circulations.


Biotransformation
Amino acids that do not enter protein synthesis are metabolized as follows: The amino group is separated from the carbon skeleton by transamination. The carbon chain is either oxidized directly to CO2 or utilized as substrate for gluconeogenesis in the liver. The amino group is also metabolised in the liver to urea.
Elimination
Only minor amounts of amino acids are excreted unchanged in the urine.