A bronchial spasm is a sporadic, uncontrollable tightening of the smooth muscle of the bronchi (airways into the lungs). During a spasm, the respiratory airways narrow severely, limiting the flow of air. A sign of bronchospasm is a cough accompanied by wheezing. This condition is often triggered by various stimuli, such as allergens like pollen or other irritants like cigarette smoke. Physical, emotional or psychological stress may also cause bronchial spasms. Viral respiratory infections often bring symptoms of bronchoconstriction as do chronic lung diseases such as emphysema and chronic bronchitis or existing inflammatory conditions, such as asthma.
There are several different classes of medication used to treat bronchial spasms. The first is preventers. Mast cell stabilisers such as cromolyn sodium fall into this category. Mast cell stabilisers prevent and reduce allergy symptoms. They help to control allergies by blocking a calcium channel that is required for cells to become unstable. When the cell is stabilised by these mast cell blockers, histamines that cause allergies and irritation, which were being released by the unstable cells, are no longer released.
Cromolyn, a mast cell stabiliser, comes in an inhaled form which can be breathed either into the mouth or into the nose. You have to take cromolyn sodium 1 to 4 weeks before it is fully useful. Thus, it is more effective in preventing bronchial spasms before they develop rather than relieving them once they've begun.
Controllers are another class of treatment. For people with asthma, using controllers such as inhaled corticosteroids and anti-leukotrienes on a regular basis is essential in preventing asthma flare-ups. These controller agents treat the underlying inflammation that causes bronchospasm by reducing bronchial swelling. Studies suggest that anti-leukotrienes may have fewer adverse effects than inhaled corticosteroids. For more severe cases, oral steroids are often prescribed.
People who have asthma or emphysema are susceptible to bronchial hyperactivity. Inflammation and narrowing of their airways can occur suddenly when they're exposed to irritants like smoke or allergens. Bronchial dilators are useful for treating quick inflammation because they provoke instant expansion of the airways. Because they're inhaled, these drugs reach the bronchial tubes very quickly. When used appropriately as rescue therapy during sudden bronchial spasms, beta-agonist inhalers (bronchodilators) can be truly life-saving; constant reliance on these beta-agonist inhalers, however, can limit their effectiveness.
Bronchodilators treat the symptoms of bronchial spasms by relaxing the smooth muscles around the airways. Most bronchodilators are prescription drugs. Some of these are albuterol (Ventolin, Proventil), bitolterol (Tornalate), terbutaline (Brethaire), pirbuterol (Maxair), metaproterenol (Alupent) and isoetharine (Bronkometer). Bronchodilators are short-acting. For those whose bronchial spasms are caused by transient illnesses like viral respiratory infections, inhalers are good short-term measures.
There are longer-acting bronchodilators as well. These often have to be combined with a steroid to be most effective. These longer acting medications are not effective for quick fixes though. They are, however, useful for the prevention of exercise-induced bronchial spasms if taken 30 minutes before exercise. It is not uncommon for these medications to last up to 12 hours.