Erdosteine is classified under the mucolytic drugs.
Pharmacology: Erdosteine pharmacologically acts as a bronchial mucus fluidifying agent.
Pharmacodynamics: Erdosteine, besides its property of fluidifying bronchial mucus thus, facilitating expectorations, shows effects as antagonizing the formation "in loco" of free radicals and as contrasting the action of elastase enzyme. Pharmacological studies show that erdosteine, as such, does not possess these properties but only after metabolism, transform into active metabolites which have the chemical -SH groups. These metabolites break the -SH groups and brings about a reduction in the mucus elasticity and viscosity thus, facilitating the expectoration.
The chemical -SH groups, distinctive of this activity, are chemically blocked and become free only after metabolism or in alkaline moiety. This property guarantees a good tolerability without bad tastes and without mercaptanic regurgitations and with good gastric tolerability.
Pharmacokinetics: Erdosteine is rapidly absorbed after oral administration; after a single oral dose, the Tmax is 1.2 hrs.
Erdosteine is rapidly metabolized into at least 3 active metabolites containing free thiol groups, which tentatively are N-thiodiglycolyl-homocysteine (metabolite I), N-acetyl-homocysteine (metabolite II) and homocysteine (metabolite III). The elimination half-life of erdosteine is 1.4 hrs on the average and that of the metabolite I and II of 1.2 and 2.7 hrs, respectively.
Multiple treatments do not modify the pharmacokinetics of erdosteine.
Age does not change the pharmacokinetics of erdosteine and of its metabolites.
In the elderly patients suffering from renal failure, whose creatinine clearance is comprised between 25 and 40 mL/min, the pharmacokinetic characteristics of erdosteine and its metabolites are not significantly different from those of the healthy elderly subjects.