Asthma Medicines

An asthmatic attack is one of the most striking medical emergencies. One of my first experiences with severe asthma was in the intensive care unit of Bellevue Hospital. I had been called to consult on a fifty-six-year-old woman who was having a severe asthmatic attack. As I entered the unit and approached the bedside, I noted several physicians already in attendance. The patient was sitting upright with labored breathing and I could hear her wheezing from several feet away. It was clear that she was not doing well despite continuous oxygen and medicated aerosol treatment. Unable to speak due to shortness of breath, her expression was one of fear and desperation. Several days later, greatly improved after vigorous treatment, I asked her to describe what she had been feeling during her attack. “It was like I was drowning.”

In the asthmatic attack there is constriction or tightening of the bronchial wall muscle, and secretion of mucus, often with “plugging” of small air tubes, as well as inflammation and swelling of the bronchial lining. The end result is blockage or obstruction of the bronchial tubes. The frequency, duration, and severity of the asthmatic attack varies markedly from patient to patient.

Share This

Since asthma has been defined as an illness characterized in part by airway obstruction it is essential for diagnosis to demonstrate this by using spirometry. The definition also includes the feature of reversibility; that is, that airflow can improve significantly. To demonstrate this feature spirometry is performed before and after inhaling bronchodilator medication. Th be significant, the physician looks for at least a 15 percent improvement in the spirometry parameters after the patient inhales bronchodilator medication.

Diseases such as emphysema, chronic bronchitis, cystic fibrosis, or bronchiectasis may demonstrate severe degrees of airflow obstruction without any improvement after bronchodilator use. However, it may be difficult to demonstrate reversibility in all asthmatics during a single laboratory session, possibly owing to severe degrees of bronchial narrowing or to inadequate inhalation of medication by the patient. Therefore, the absence of reversibility should never be taken as absolute proof that asthma is not present.

Check out asthma home remedies 

Share This

The B-agonists were developed in the 1940s, with isoproterenol the first of the class. Like epinephrine (adrenaline) this agent has both beta-1 and beta-2 effects. Isoetharine was one of the first”selective”B2-adrenergic agonists introduced in the United States and it was followed by metaproterenol. With the development of selective B2-adrenergic agonists there is no place for the use of nonselective agents that have significant stimulatory effects on the heart and circulation. Further research has produced more potent and longer-acting selective agents.

For the Acute Asthmatic Attack: Short-Acting Agent

Several selective B2-adrenergic agonists are available for use. These agents are available as aerosol sprays delivered by metered-dose inhalers (MDIs), aerosol solution to be delivered by nebulization, dry powders for inhalation (DPI), short and long-acting tablets, and as syrups flavored for children. In the acute asthmatic attack the treatment of choice for prompt relief of symptoms is the administration of a short-acting B2-adrenergic agonist. B2-adrenergic agonists (albuterol, metaproterenol, pirbuterol, terbutaline, fenoterol, and bitolterol) have a rapid onset of action (within minutes) with a duration of action of four to six hours. The recommended dosage is two puffs every six hours as needed. These medications differ in potency as well as how fast they begin to work and when their peak effect is reached. There are also differences in how long the effect of the drug lasts. Fenoterol has never been made available in the United States. Its extremely rapid onset of action may have contributed to its overuse and it has been implicated in cases of fatal asthma in New Zealand. Table 1 lists the B2-agonists by generic and brand name as well as the types of preparations that are available.

Share This

Many patients fear they will become addicted to their asthma medications and be unable to stop their use. This may partly be due to dependence on medication for the relief of symptoms and attacks. This fear of addiction may explain why some patients do not take their medications.

There is no evidence of the development of addiction to asthma medications. When good control of asthma is achieved, it is often possible to reduce or discontinue medication that is no longer needed. However, good control must come first since withdrawal of medication may result in increased frequency of attacks.

Adrenal Insufficiency

In the case of systemic corticosteroids, the management of reduction and withdrawal of these agents must be closely supervised in view of possible adrenal insufficiency. Patients with severe asthma may become “steroid dependent” for control of their disease, but that does not represent an addiction to medication.

Are There Delay Effects of Asthma Medications?

Patients may be concerned whether long-term use of asthma drugs will have serious adverse effects, another reason why patients may reduce or eliminate medications on their own.

Long-term use in adults of the B-agonists, theophylline, cromolyn sodium, and inhaled corticosteroids have not shown any evidence of delayed adverse effects. In children, inhaled corticosteroids may have adverse effects on growth and bone development. These agents may still be necessary, however, when the risk of severe, uncontrolled asthma out-weighs the possible detrimental effects on bone growth. Nedocromil and ipratropium bromide are still relatively new and long-term experience with these agents is forthcoming. At this time there is no evidence of possible delayed adverse effects of these agents.

Oral Corticosteroids

In both children and adults, long-term effects of the oral corticosteroids must be anticipated. These effects are outlined above and must be weighed against the dangers of uncontrolled asthma. Once systemic steroids are required there should be frequent review of their necessity with the goal of reducing dosage or withdrawal if possible. Alternate-day administration should always be considered if patients must remain on oral corticosteroids.

Share This