Occupational exposure must be explored as more than 200 different occupational asthma triggers have been reported in the medical literature. The concept of total body burden of toxic and allergy factors is very important here. To prevent and treat asthma attacks, the goal is to reduce exposure to toxic and allergenic substances as much as possible to lower the total body burden.

Use of Bronchodilator Drugs by Conventional Physicians to Manage Asthma
Frequently, an asthma attack may be precipitated by a bacterial infection. In such a case, an antibiotic medication is helpful in clearing up the infection. During severe attacks, respiration may be limited so much that the oxygen concentration in the bloodstream may be dangerously low. Breathing in oxygen will help to correct this situation. Aside from oxygen and antibiotics, the medications to treat both acute and chronic asthma are classified into two categories, bronchodilators and anti-inflammatory agents. Together, these medications are used to reverse or prevent air flow obstruction. The smooth muscles of the airways contain receptors that are known as beta 2-adrenergic receptors. Upon stimulation, these receptors cause a relaxation of the smooth muscles of the bronchi.

A hormone in our body that stimulates this type of receptor is adrenaline or epinephrine, which is the fight or flight hormone secreted by the adrenal medulla. The drugs used to stimulate these receptors are called beta 2- adrenergic agonists. One of the most used of these drugs is albuterol whose brand names are Proventil or Ventolin. They are administered mostly by metered dose inhalers (abbreviated MDI). For severe attacks, albuterol may be administered in the hospital by nebulizer every one or two hours. However, the frequency is reduced as soon as possible, and the patient is switched to the metered dose inhaler. Outside of the hospital the medication is used as necessary, preferably only one or two puffs daily. It may be used prior to exercise to prevent an exercise induced asthmatic attack.

Although the product literature states that up to 12 puffs a day may be used, patients with mild asthma should need these drugs only 3 or 4 time a week. A pattern of regular or increasing use approaching 8 to 12 puffs a day reflects poor asthma control and warrants immediate re-evaluation. Although these beta 2-adrenergic agonists are reported to be reasonably safe, they do stimulate the autonomic nervous system and may produce rapid or irregular heartbeat, insomnia, shakiness and nervousness.

Anti-cholinergic agents constitute the second class of bronchodilators. Whereas the beta 2-adrenergic agonists mimic the sympathetic nervous system, the anti-cholinergic agents work by inhibiting the parasympathetic nervous system as the latter tends to constrict the bronchi. So by inhibiting the action of the parasympathetic nervous system with anti-cholinergic drugs like ipratropium bromide or Atrovent, bronchodilation is promoted. Atrovent is also given by inhaler. Potential adverse effects include dry mouth, cough, headaches, a worsening of glaucoma and urinary retention.

A third class of bronchodilators are the methylxanthines, such as aminophylline and theophylline. Caffeine is another example of a methyl xanthine, although it is not used in asthma. The exact mechanisms of action of the methylxanthines in causing bronchodilation is unclear. Previously, these drugs had been considered the first line of therapy for asthma, but because of their serious side effects, they are somewhat less important at the present time. However, aminophylline or theophylline may be used intravenously if other treatments have not gotten an attack under control.