Pharmacotherapeutic group: Erdosteine is classified under the mucolytic drugs.
Pharmacology: Pharmacodynamics: Mechanism of action/pharmacodynamic effects: Erdosteine, active ingredient of Erdos Capsule 300 mg, besides its property of fluidifying bronchial mucus thus facilitating expectoration in animal studies, it prevents the accumulation of free oxygen radicals when their production is accelerated and increases antioxidant cellular protective mechanisms as well as counteract the action of elastase enzyme.
From pharmacological studies results that erdosteine, per se, does not possess these properties but only after metabolization. In fact, the chemical SH groups, distinctive of this activity, are chemically blocked and become free only after metabolization or in alkaline moiety. This property guarantees a good tolerability without bad tastes and without mercaptanic regurgitations and with good gastric tolerability.
Pharmacodynamic properties: Mucolytic agent reducing the viscosity of mucus and purulent sputum.
Erdosteine is a prodrug, becoming active after metabolism whereby free thiol groups are formed. This effect is due to the opening of the disulfide bonds of the bronchial mucoproteins.
It has also been demonstrated that erdosteine inhibits bacterial adhesion to epithelial cells. Due to the presence of a free thiol group in its active metabolite, erdosteine has a significant antioxidant action, demonstrated by both 'in vitro' and 'in vivo' studies.
Pharmacokinetics: Absorption: Erdosteine is quickly absorbed after oral administration and rapidly transformed through a first-pass metabolism to its biologically active metabolite - N-thiodiglycolylhomocysteine (M1). After administration of 300 mg, the peak plasma concentration of erdosteine (Cmax) 1.26±0.23 µg/ml was reached 1.18±0.26 hour after administration (Tmax), while M1 showed a Cmax of 3.46 μg/ml and a Tmax of 1.48 hour.
The plasma concentrations of erdosteine increase in a dose-dependent manner. Plasma concentrations of M1 increased also with the dose, but not as proportionally as in the case of unchanged erdosteine.
The absorption is independent from food intake.
Distribution: In animal models, erdosteine was distributed mainly to kidneys, bone, spinal cord and liver. Pharmacologically active concentrations of both erdosteine and M1 were found in broncho alveolar lavage.
Elimination: The elimination T1/2 is 1.46±0.60 h and 1.62 ±0.59 h, respectively, for erdosteine and M1. In urine, only M1 and sulphates were found, faecal elimination is negligible.
No accumulation or change in the metabolism of erdosteine and M1 has been observed after oral administration of 600 to 900 mg daily for 8 days.
Influence of age: Age does not affect the pharmacokinetics of erdosteine.
Binding to plasma proteins: Plasma proteins of erdosteine is 64.5% (range: 50-86%).
Toxicology: Preclinical safety data: Preclinical safety data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity and toxicity to reproduction.