Bronchial asthma is a chronic, relapsing disease of the respiratory system, which affects many people, both adults and children. Asthma is one of the most extended diseases worldwide. Unfortunately, at present there is a substantial increase in the incidence of bronchial asthma in many countries. There are many reasons for this, and they are actively studied. Environmental insults, immunity disorders and some modifications of the genetic nature are on importance. The incidence of asthma in the world is from 4 to 10%. Usually asthma has attacks of choking or difficulty breathing when it is more difficult to exhale than inhale. Often this involves wheezing that can be clearly heard at a distance. For example, if a doctor puts an ear or a stethoscope to the chest of a patient, he/she can hear the distinctive "whoosh" located on the whole surface. Exhalations become longer, sometimes 2 - 4 times longer than the duration of inhales. Asthma can sometimes be atypical. With noticeable breathing discomfort, a patient is concerned about attacks of compulsive dry cough. There is also often "whoosh" in the chest. About ten clinical variants of bronchial asthma are emitted (Bjorklund, 2005).
A number of cellular elements take place in the development of inflammatory process. These are eosinophilias, mast cells and macrophages. Along with them epithelial cells, fibroblasts, endothelial cells are on importance in the development and maintenance of inflammation in the bronchial wall. All the cells in the activation process secrete a number of biologically active substances (leukotriene, cytokines, chemotactic factors, platelet-activating factor), which have pro-inflammatory effects. As a result of these changes bronchial obstruction is formed, caused by swelling of the mucous membrane of bronchial tree, hyper secretion of mucus, spasm of smooth muscles of the bronchi and sclerotic changes in the walls of the bronchial tubes. Inflammation is a mandatory component of allergic lung disease. It is very important that the chronic inflammation is found in the bronchial wall, even in periods of sustained remission of asthma. The pathogenesis of asthma is bronchial hyper reactivity, which is a direct result of inflammation in the bronchial wall. Bronchial hyper reactivity is property of airways to respond on various specific (allergic) and nonspecific (cold, damp air, pungent smells, exercise, and laughter) incentives that are indifferent for healthy people. Nonspecific bronchial hyper responsiveness is a universal feature of asthma: the higher hyper reactivity, the more difficult asthma is. Malfunctions of the endocrine system are significant in the pathogenesis of asthma: glucocorticoid insufficiency, increased activity of the thyroid hormones and hyper estrogens. Almost all the patients in the development of asthma have changes in the central and autonomic nervous system (Bjorklund, 2005).
Three phases of asthma are distinguished:
- Biological defects of bronchial reactivity in healthy people.
- A mild state of asthma.
- Symptomatic asthma.
First of all, asthma should be classified according to severity. Severity is determined by the following factors:
- A number of night time symptoms in a week.
- A number of day time symptoms in a week.
- Evidence of malfunctions of physical activity and sleep.
According to the level of obstruction, the severity and reversibility of bronchial asthma is divided into:
- Mild persistent.
- Severe (Gershwin & Albertson, 2011).
There are some complications that are caused by asthma: emphysema, respiratory failure, atelectasis, pneumothorax, myocardial degeneration, heart failure.
Asthma medicines play an important role in controlling condition of a patient. Asthma is a disease characterized by inflammation of respiratory tracts, which causes recurring symptoms: shortness of breath, cough and mucus production. Only appropriate treatment will help prevent attacks of breathlessness and lead a normal life. Medicines for asthma are aimed at:
- Control of inflammation and prevent symptoms such as choking or coughing during the night, early morning hours or after exercises (for long therapy).
- Relief of asthma attacks (emergency relief of symptoms) (Cichorski, 2008).
There are two types of medicines for protracted control of the disease and relief of symptoms.
- Anti-inflammatory drugs. This is a major type of therapy for patients with asthma, since drugs of this group are constantly working to prevent attacks. Steroids are extremely necessary anti-inflammatory drugs. They reduce mucus and swelling in the airways. Consequently, respiratory tract becomes less sensitive to effects of stimuli.
- Bronchodilators. Asthma medicines of this group relieve symptoms by relaxing bronchial muscles, narrowing the lumen of airway. As a result, the lumen of bronchial is rapidly expanding, contributing large amount of air entering lungs and back. In the issue, breathing improves. Bronchodilators help move away mucus from lungs. With the expansion of luminal, mucus moves freer and it is easier to cough up.
There are different versions of purpose of these drugs. Treatment can be successful if a person enjoys a full, active life. If symptoms of asthma are not controlled, a patient should contact a professional for a new therapy that will bring desired results (Sampson, 1999).
Doctors and specialists in the field of asthma point out two main elements of the disease: narrowing of the bronchi and airway inflammation. Studies have shown that the reduction and prevention of further inflammatory processes is essential to prevent asthma attacks, hospitalization and death. Drugs for prolonged control of the disease are taken every day for a long time to maintain control of asthma (symptoms are shown several times a week and asthma attacks affect the activity). Very effective medications of this group are anti-inflammatory drugs. They stop inflammation. However, there are other drugs that are often used in conjunction with anti-inflammatory to strengthen the action of the latter (Gershwin & Albertson, 2011).
Medicines for prolonged control of asthma include:
- Corticosteroids ( drug for treatment of persistent asthma, any drug in this group is received in inhaled form).
- Beta-agonists (they should be used only in conjunction with anti-inflammatory drugs).
- Combination therapy (inhaled corticosteroids + long-acting beta-agonists is a modern class of drugs, that achieves asthma control while using lower dose of steroids).
- Leukotriene modifiers (have less pronounced inflammatory effects than steroids).
- Theophylline (it is used in combination with anti-inflammatory drug. It is currently of limited use).
- Stabilizers of fat cell membranes (weak anti-inflammatory drugs).
- Antibody immunoglobulin (injectable medications prescribed to patients with severe allergic asthma that is not well controlled by inhaled steroids).
Medications for quick relief of asthma symptoms are used for emergency relief of symptoms during an episode of asthma (cough, feeling of fullness in the chest and wheezing - signs of bronchoconstriction). Drugs of this group include:
- Beta-agonists of short-acting (any group of bronchodilators to relieve asthma attacks and prevent asthma symptoms caused by exercises).
- Anticholinergic (bronchodilators that are necessary given in combination with beta-agonists for quick action or as an alternative to these drugs).
- Systemic corticosteroids (anti-inflammatory drugs for the relief of acute exacerbations of asthma. They quickly deal with the attack at the time of selection of other treatment and speed recovery) (Gershwin & Albertson, 2011).
Asthma medicines can be applied in different ways: they can be breathed in through the metered dose inhaler, dry powder inhaler or nebulizer. They can be taken orally as a pill or liquid. Some of the drugs are used in the form of subcutaneous injections. Some asthma medicines can be used simultaneously. For example, some inhalers contain combination of two different drugs. Thanks to one device the body receives both means at the same time; respectively reducing the number of inhalers that are required to treat the symptoms of asthma. Inhalation forms are the most effective and safe. The medicine is delivered precisely where it is needed, in the bronchi. Action develops quickly, the highest concentrations are in the respiratory tract, and systemic (overall) effect is minimized. Many drugs can only be used in inhalation as they are not absorbed while taking inside. Other medications just in a form of inhalation act topically, which increases not only their efficiency but also safety (inhalation hormones). The most common form of inhaler is dose aerosol inhaler. It is activated by pressing the spray. Its drawback is that many patients have difficulties with coordination of breath and pressing. This can be overcome either by special education, or by using a spacer (tank chamber, creating additional volume). Other forms of inhalers are metered dose aerosol inhaler, which is activated by breath, a dry powder inhaler (capsule, tank, and multi-dose) and nebulizers (from the word “nebula” that means fog) - devices that convert liquid medication into aerosol; it is easy to penetrate them even into restricted bronchi. If difficulty in breathing is rare and is easily removed with an inhaler, it will be possible and necessary to do without a permanent cure. However, if a person needs an inhaler four times a week, he should be treated. Anti-inflammatory therapy does not eliminate already caused symptoms and attacks, but prevents their further appearance. In addition, even in rare but severe exacerbations, basic therapy is needed: mild asthma with severe exacerbations is treated as moderate. It is in interests of a patient (Hansel, 2001).
In the treatment of asthma the "step" approach is currently using, in which the intensity of treatment varies depending on the severity of asthma. Stepwise approach to asthma therapy is recommended because asthma occurs in different ways for different people and one and the same person at different time. The goal is to achieve asthma control with the least amount of drugs. Quantity and frequency of medication increase (steps up) if asthma worsens, and decrease (steps down), if asthma is well controlled for 3 months at least. According to several studies, it is more effective to assign more active therapy, and then reduce it on a "step down" and not vice versa (Cichorski, 2008).
Bronchial asthma is an incurable disease. Reception frequency of asthma medicines depends on the severity of the individual case and the frequency of symptoms. For example, if symptoms are only shown during the allergy season, a dose of drugs to control them is only required during this period. However, such a form of the disease is unusual, and most asthmatics have to take medications every day (Gershwin & Albertson, 2011).