How much and how often should you use the product?
Only use the salbutamol inhaler when you need it such as when you start coughing, wheezing, or experience shortness of breath or tightness in your chest. You can also use your inhaler prior to doing activities that will cause you to become breathless, such as sports, walking long distances, or climbing the stairs.
The common way to use the inhaler (for both adults and children) is:
- 1 or 2 puffs when necessary
- Up to a maximum or 4 times total in 24 hours
In the event of a sudden asthma attack, you can take more than the normal number of puffs (up to 10). Wait for 30 seconds and shake the Ashtmagen inhaler between doses. Repeat the dose 10 minutes later.
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.