How much and how often should you use the product?
Salbutamol nebuliser solution should be administered by a suitable nebuliser, via a face mask or T-piece, or via an endotracheal tube.
To open the plastic ampoule, take a strip of ampoules from the foil pack, remove one ampoule, replacing the rest back in the foil pack, and replace the foil pack back in the carton. Hold the ampoule upright and open it by twisting off the top. Squeeze the liquid into the solution holder of the machine.
Adults: The usual starting dose is 2.5mg as a single dose. This may be increased to 5mg depending on the advice from your physician. Treatment may be repeated up to four times a day.
For the treatment of severe airways obstruction in adult hospitalised patients, higher doses up to 40mg per day can be given only under strict medical supervision.
Children aged 12 years and over: Same as adults.
Children aged 4 to 11 years: 2.5mg to 5mg up to four times a day.
Children under 4 years of age: Should use other forms of salbutamol sulfate.
Salbutamol nebuliser solution is designed to be used undiluted. However, if a prolonged delivery time is indicated (more than 10 minutes), then dilution with Sodium Chloride Solution (0.9%w/v) for Nebulisation or sterile sodium chloride injection (normal saline) may be required.
Mechanism of action:
In vitro studies and in vivo pharmacologic studies have shown that salbutamol has a preferential effect on beta2-adrenergic receptors compared with isoproterenol. Although beta2 adrenoceptors are the predominant adrenergic receptors in bronchial smooth muscle and beta1 adrenoceptors are the predominant receptors in the heart, there are also beta2-adrenoceptors in the human heart comprising 10% to 50% of the total beta-adrenoceptors. The precise function of these receptors has not been established, but their presence raises the possibility that even selective beta2-agonists may have cardiac effects.
Activation of beta2-adrenergic receptors on airway smooth muscle leads to the activation of adenyl cyclase and to an increase in the intracellular concentration of cyclic-3′,5′-adenosine monophosphate (cyclic AMP). This increase of cyclic AMP leads to the activation of protein kinase A, which inhibits the phosphorylation of myosin and lowers intracellular ionic calcium concentrations, resulting in relaxation. Salbutamol relaxes the smooth muscles of all airways, from the trachea to the terminal bronchioles. Salbutamol acts as a functional antagonist to relax the airway irrespective of the spasmogen involved, thus protecting against all bronchoconstrictor challenges. Increased cyclic AMP concentrations are also associated with the inhibition of release of mediators from mast cells in the airway.
Salbutamol has been shown in most controlled clinical trials to have more effect on the respiratory tract, in the form of bronchial smooth muscle relaxation, than isoproterenol at comparable doses while producing fewer cardiovascular effects. Controlled clinical studies and other clinical experience have shown that inhaled albuterol, like other beta-adrenergic agonist drugs, can produce a significant cardiovascular effect in some patients, as measured by pulse rate, blood pressure, symptoms, and/or electrocardiographic changes.
A measurable decrease in airway resistance is typically observed within 5 to 15 minutes after inhalation of salbutamol. The maximum improvement in pulmonary function usually occurs 60 to 90 minutes after salbutamol treatment, and significant bronchodilator activity has been observed to persist for 3 to 6 hours.