NAC long Mechanism of Action

Pharmacotherapeutic group: Cough and cold preparations, expectorants, excl. combinations with cough suppressants, mucolytics. ATC code: R05CB01.
Pharmacology: Pharmacodynamics: Mechanism of action and pharmacodynamic effects: Acetylcysteine is a mucolytic agent that reduces the viscosity of purulent and nonpurulent pulmonary secretions and facilitates their removal by coughing, postural drainage, or mechanical means. Acetylcysteine exerts mucolytic action through its free sulfhydryl group which opens up the disulfide bonds in the mucoproteins thus lowering mucous viscosity.
Pharmacokinetics: Absorption and distribution: Following oral administration, acetylcysteine is rapidly absorbed from the gastrointestinal tract and peak plasma concentrations occur about 0.5 to 1 hour. Due to the high first pass effect, the bioavailability of orally administered acetylcysteine is very low and mean values have ranged from 4 to 10%. The volume of distribution of total acetylcysteine was reported to range between 0.33 and 0.47 L/kg. Protein binding of acetylcysteine is about 50%.
Biotransformation: Acetylcysteine is mainly deacetylated to cysteine in the liver. Most of this is processed in the amino acid metabolism. Moreover, it forms reversible disulfide compounds with amino acids and proteins with free sulfhydryl groups.
Elimination: Renal clearance may account for about 30% of total body clearance, which was 0.211 L/h/kg.
The terminal half-life of total acetylcysteine was 6.25 hours after oral doses.