<p>Levosalbutamol Nebuliser Solution is a sterile, clear, colorless, preservative-free solution of the hydrochloride salt of Levosalbutamol, the (R)-enantiomer of the drug substance racemic salbutamol. Levosalbutamol Hydrochloride is a relatively selective &beta;2&nbsp;adrenergic receptor agonist.<br />
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Activation of &beta;2 adrenergic receptors on airway smooth muscle leads to the activation of adenylcyclase and to an increase in the intracellular concentration of cyclic AMP. This increase in cAMP leads to the activation of protein kinase A, which inhibits the phosphorylation of myosin and lowers intracellular ionic calcium concentrations, resulting in relaxation. Levosalbutamol relaxes the smooth muscles of all airways, from the trachea to the terminal bronchioles. Levosalbutamol acts as a functional antagonist to relax the airway irrespective of the spasmogen involved, thus protecting against all bronchoconstrictor.</p>