Duro-Tuss Ax Mechanism of Action

Mucolytic.
Pharmacology: Sustained-release capsule: This medicine contains ambroxol hydrochloride, which is a derivative of the mucolytic, bromhexine, which has been found to possess secretolytic and mucokinetic properties. Ambroxol hydrochloride accelerates mucus transport, promoting expulsion of thick, tenacious secretions from the respiratory tract.
Pharmacodynamics: Syrup: Mechanism of Action and Pharmacodynamic effects: Ambroxol is the active metabolite of bromhexine. Ambroxol causes an increase in secretion in the respiratory tract. It promotes surfactant production and stimulates ciliary activity. These effects assist the flow of mucus and its removal (mucociliary clearance).
An improvement in mucociliary clearance was demonstrated in clinical pharmacological studies. The increase in secretion and mucociliary clearance facilitates expectoration and reduces the cough.
Pharmacokinetics: Syrup: Absorption: Ambroxol normal release formulations are absorbed swiftly and almost completely after oral administration. Oral bioavailability is approx. 60% owing to the first-pass effect.
Plasma concentrations are in a linear relationship to the dose. Peak plasma levels are attained after 0.5 to 3 hours.
Distribution: Bioavailability of ambroxol hydrochloride is not affected by food. Plasma protein binding is around 90% in the therapeutic range. After oral intravenous and intramuscular administration ambroxol is distributed swiftly and extensively from the blood into the tissues. The highest active ingredient concentrations are measured in the lung.
Metabolism: Studies in human liver microsomes showed that CYP3A4 is the predominant isoform for ambroxol metabolism. Otherwise ambroxol is metabolized in the liver mainly by conjugation.
Elimination: Around 30% of an oral dose is eliminated via the first-pass effect. The terminal half-life is about 10 hours. Total clearance is the region of 660 mL/min, and renal clearance is 8% total clearance.
Children, Elderly, Gender: Age and gender do not affect the pharmacokinetics of ambroxol to any clinically relevant extent; therefore adjustment of the dose in unnecessary.
Renal Impairment: An accumulation of metabolites (predominantly conjugates of the parent substance) cannot be ruled out in severe renal impairment.