Asthma medicine
Asthma is a pulmonary disease characterized by reversible airway obstruction, airway inflammation, and increased airway responsiveness to a variety of stimuli. Asthma, bronchitis and emphysema are known as chronic obstructive pulmonary diseases (COPD). COPD is characterized as generalized airways obstruction, particularly of small airways, associated with varying degrees of symptoms of chronic bronchitis, asthma, and emphysema. Asthma is a reversible obstructive pulmonary disorder (ROPD) characterized by increased responsiveness of the airway, resulting in airway obstruction. Airway obstruction is defined as an increased resistance to air flow during forced expiration. In asthma, airway obstruction typically results from bronchospasm. Asthma is characterized by bronchoconstriction, excessive mucus production, and inflammation and swelling of airways. These conditions cause widespread and variable airflow obstruction thereby making it difficult for the asthma sufferer to breathe. Asthma further includes acute episodes or attacks of additional airway narrowing via contraction of hyper-responsive airway smooth muscle. Other obstructive diseases such as COPD may also have a reversible component caused by one or more of the above mentioned three elements. Bronchial asthma may be defined as a clinical syndrome characterized by outbursts of suffocation and of severe discomfort, especially when air is exhaled from the lungs. These asthma outbursts or asthma attacks often occur after exertions or during the night, are reversible either spontaneously or following treatments and are generally the result of bronchial obstructions. Three major factors contribute to these obstructions: a spasm (contraction) of the smooth muscles surrounding the airways, an inflammation of the bronchial walls accompanied by an effusion of fluid (oedema) and an hypersecretion of mucus. Mild asthma is defined as brief episodes of wheezing, with or without dyspnea or cough. Moderately severe asthma is defined as wheezing and dyspnea, and can be with or without cough and expectoration, but generally interferes with daily activities and/or sleeping. Severe asthma is characterized by incapacitation due to dyspnea, and the afflicted patient typically is unable to eat or sleep normally, is very anxious, and is often exhausted. Exercise-induced asthma (EIA) is a condition of respiratory difficulty that is triggered by aerobic exercise lasting several minutes. Asthma is managed pharmacologically by long term control through use of anti-inflammatories and long-acting bronchodilators and short term management of acute exacerbations through use of short-acting bronchodilators. One of these types of treatments employs quick-relief medications, such as inhaled bronchodilator therapy, which works quickly to suppress symptoms by relaxing airway smooth muscle. The other of these types of treatments employs long-term preventive medications, such as inhaled, oral, or intramuscular corticosteroids, and leukotriene antagonists, which can prevent the onset of symptoms and attacks by controlling the underlying inflammation, thereby keeping persistent asthma under control. Inhalation has become the primary route of administration in the treatment of asthma. This is because, in addition providing direct access to the lungs, medication delivered through the respiratory tract provides rapid and predictable onset of action and requires lower dosages compared to the oral route. Typical delivery systems for inhalable drugs are the pressurized metered-dose inhaler (pMDI) comprising a suspension of fine drug particles in a propellant gas, and the dry powder inhaler (DPI) comprising fine drug particles as dry powder typically admixed with coarser excipient such as lactose.
Related products