Asthma is an inflammatory disease characterized by generally reversible obstruction of the lower airways often following sensitization by allergens. However, sometimes bronchial obstruction can be irreversible.
Many cells play an important role, in particular mast cells, eosinophil granulocytes and T lymphocytes. In predisposed subjects this inflammation causes recurrent episodes of wheezing and whistling breath, difficulty in breathing, chest tightness and coughing. These episodes occur generally as “crises”, with periods of relative well-being between one crisis and another.
The symptoms listed are usually associated with diffuse but variable reversible bronchoconstriction following bronchodilator therapy or can occur spontaneously. Inflammation also causes an increase in the airway response to numerous more or less specific stimuli.
The risk factors for asthma are numerous, with genetic and environmental origins, and each factor can contribute to a varying degree in the manifestation of the disease. The main risk factors are genetic predisposition, allergies, infections, diet, hygienic conditions, air pollution and physical activity.
Asthma can be a consequence of renal bronchial syndrome of the upper airways. The main pathophysiological alteration that determines the symptomatology of the asthmatic patient is reduction of the airway calibre.
Currently, excellent results are obtained by having the patient take the drugs regularly as an aerosol, spray or in the form of inhalation powder in order to stem the chronic inflammation and prevent it from degenerating, as well as to stem the bronchospasm, “enlarging” the bronchi when these tend to shrink. In any case, it is the specialist who decides on a case-by-case basis the most suitable drug to prescribe, while the asthmatic must always be aware of the medications he or she is taking and know how and when to change the dosage, according to the doctor’s instructions.
In order to limit the inflammation of the airways within the normal parameters and consequently to avoid the accentuation of “bronchial hyperreactivity”, it is recommended to take anti-inflammatory products on a continuous basis.
Corticosteroids, whether derived or cortisone-based drugs, promptly inhibit the release of endogenous factors responsible for the inflammatory process. Some of the most common inhalation steroids for inhalation therapy are beclometasone, budesonide, flunisolide and fluticasone. Inhaled steroids form the cornerstone of asthma therapy. They are only minimally absorbed in the blood and the patient is therefore not hampered by the side effects of steroid drugs given via systemic administration (i.e., taken orally, as an intramuscular or intravenous injection).
Bronchodilator drugs differ according to the rate at which they begin to function. Long-acting bronchodilators (LABAs), such as formoterol, indacaterol, clembuterol, salmeterol and others, have a prolonged action (about 12 hours). Among these formoterol also is fast acting, unlike salmeterol. They are background drugs to be combined with an inhaled steroid in case the asthma is not adequately controlled. These are safe drugs when administered in combination with the inhaled steroid.
In the event of a crisis, however, the subject may resort to another category of drugs called short-acting bronchodilators (SABAs), among which the most common is salbutamol.