Salbutamol is a beta-adrenergic stimulant association of salbutamol and beclomethasone dipropionate is specially provided
Salbutamol is a beta-adrenergic stimulant that has a highly selective action on the receptors in bronchial muscle, resulting in bronchodilation Beclomethasone dipropionate is a synthetic glucocorticoid with a potent anti-inflammatory activity and weak mineralocorticoid activity. This association of salbutamol and beclomethasone dipropionate is specially provided for those patients who require regular doses of both drugs for treatment of their asthma obstructive airways disease.
Pharmacodynamics AEROCORT Inhaler is a combination of beclomethasone dipropionate and salbutamol, which have different modes of action and show additive effects. Salbutamol: The primary action of beta-adrenergic drugs, including salbutamol, is to stimulate adenyl cyclase, the enzyme which catalyses the formation of cyclic-3,5-adenosine monophosphate (cyclic AMP) from adenosine triphosphate (ATP) in beta-adrenergic cells. The cyclic AMP thus formed mediates the cellular responses
Increased cyclic AMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells. Glucocorticoids have been shown to inhibit multiple cell types ( mast cells, eosinophils, basophils, lymphocytes, macrophages, and neutrophils) and mediator production or secretion.
Because of its gradual absorption from the bronchi, systemic levels of salbutamol are low after inhalation at recommended doses Administration of tritiated salbutamol by inhalation to four subjects resulted in maximum plasma concentrations within 2 to 4 hours Due to the insensitivity of the assay method, the metabolic rate and half-life of elimination of salbutamol in plasma could not be determined. However, data from urinary excretion studies indicated that salbutamol has an elimination half-life of 3.
Approximately 72% of the inhaled dose is excreted in the urine within 24 hours - 28% as unchanged drug and 44% as metabolite. Beclomethasone dipropionate when administered via inhalation there is extensive conversion of beclomethasone dipropionate to the active metabolite, beclomethasone 17-monopropionate (B-17-MP), within the lungs prior to systemic absorption. The systemic absorption of B-17-MP arises from both lung deposition and oral absorption of the swallowed dose.
When administered orally in healthy male volunteers, the bioavailability of beclomethasone dipropionate is negligible, but pre-systemic conversion to B-17-MP results in 41% (95% CI 27-62 %) of the dose being available as B-17-MP.Beclomethasone dipropionate is cleared very rapidly from the systemic circulation, owing to extensive first-pass metabolism. The main product of metabolism is the active metabolite (B-17-MP). Minor inactive metabolites, beclomethasone-21-monopropionate (B-21-MP) and beclomethasone (BOH), are also formed, but these contribute little to systemic exposure. The tissue distribution at steady state for beclomethasone dipropionate is moderate (20L), but more extensive for B-17-MP (424L). Following oral administration of tritiated beclomethasone dipropionate, approximately 60% of the dose was excreted in the faeces within 96 hours, mainly as free and conjugated polar metabolites. AEROCORT Inhaler is contraindicated in patients with a history of hypersensitivity to any of the components of the drug product. AEROCORT Inhaler is not for use in acute attacks, but for routine long-term management; so, some patients will require a separate Asthalin Inhaler for relief of acute bronchospasm. For those patients who are steroid-dependent, it is advisable to commence therapy with beclomethasone diproprionate ( Beclate Inhaler ) as a separate inhaler. Patients who have been weaned in the previous few months from long-term systemic corticosteroids need special consideration until the hypothalamic-pituitary-adrenal system has recovered sufficiently to enable the patient to cope with emergencies such as trauma, surgery, or infections. These patients should also be given a supply of oral steroids to use in an emergency when their airways obstruction worsens.
Tags: AEROCORT Inhaler, Beclomethasone dipropionate, beta-adrenergic, Inhaler, oral steroids, Salbutamol