Severe bronchospasm
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 β2 adrenergic receptor agonist.
Activation of β2 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.
Other short-acting sympathomimetic aerosol bronchodilators or epinephrine should be used with caution with Levosalbutamol. If additional adrenergic drugs are to be administered by any route, they should be used with caution to avoid deleterious cardiovascular effects.
Beta-blockers: Beta-adrenergic receptor blocking agents not only block the pulmonary effect of beta-agonists such as Levosalbutamol Nebuliser Solution or Inhaler, but may also produce severe bronchospasm in asthmatic patients. However, under certain circumstances, e.g. prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta-adrenergic blocking agents in patients with asthma. In this setting, cardio selective beta-blockers could be considered with caution.
Diuretics: The ECG changes and/or hypokalemia that may result from the administration of non-potassium sparing diuretics can be acutely worsened by beta-agonists when the recommended dose of the beta-agonist is exceeded.
Digoxin: It is necessary to carefully evaluate the serum digoxin levels in patients who are currently receiving digoxin and Levosalbutamol Nebuliser Solution or Inhaler.
Monoamine Oxidase Inhibitors or Tricyclic Antidepressants: Levosalbutamol Nebuliser Solution or Inhaler should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents.
Pregnancy: There are no adequate and well-controlled studies of Levosalbutamol Nebuliser Solution in pregnant women. Levosalbutamol Solution should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Lactation: It is not known whether Levosalbutamol is excreted in human milk. Caution should be exercised when Levosalbutamol Nebuliser Solution is administered to a nursing woman.
