Asthma

Asthma is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness, and coughing. It is also known as bronchial asthma or exercise-induced asthma.

What causes asthma and who is at risk?

Asthma is caused by inflammation in the airways. When an asthma attack occurs, the muscles surrounding the airways become tight and the lining of the air passages swell. This reduces the amount of air that can pass through the airways and can lead to wheezing sounds.

Most people with asthma have wheezing attacks separated by symptom-free periods. Some patients have long-term shortness of breath with episodes of increased shortness of breath. Still, in others, a cough may be the main symptom. Asthma attacks can last from minutes to days and can become dangerous if the airflow becomes severely restricted.

In sensitive individuals, asthma symptoms can be triggered by breathing in allergy-causing substances (called allergens or triggers). Triggers include pet dander, dust mites, cockroach allergens, molds, or pollens. Asthma symptoms can also be triggered by respiratory infections, exercise, cold air, tobacco smoke and other pollutants, stress, food, or drug allergies. Aspirin and other non-steroidal anti-inflammatory medications (NSAIDS) provoke asthma in some patients.

Approximately 20.5 million Americans currently have asthma. Many people with asthma have an individual or family history of allergies, such as hayfever (allergic rhinitis) or eczema. Others have no history of allergies.

Symptoms

Symptoms of asthma include:

  • Wheezing
  • Usually begins suddenly
  • Comes in episodes
  • May be worse at night or in early morning
  • Gets worse with cold air, exercise, and heartburn
  • May go away on its own
  • Is relieved by bronchodilators (drugs that open the airways)
  • Cough with or without sputum (phlegm) production
  • Shortness of breath that gets worse with exercise or activity
  • Intercostal retractions (pulling of the skin between the ribs when breathing)

Emergency symptoms:

Additional symptoms that may be associated with this disease:

  • Nasal flaring
  • Chest pain
  • Tightness in the chest
  • Abnormal breathing pattern --breathing out takes more than twice as long as breathing in
  • Breathing temporarily stops

Diagnosis

Allergy testing may be helpful in identifying allergens in patients with persistent asthma. Common allergens include pet dander, dust mites, cockroach allergens, molds, and pollens. Common respiratory irritants include tobacco smoke, pollution, and fumes from burning wood or gas.

The doctor will use a stethoscope to listen to the lungs. Asthma-related sounds may be heard. However, lung sounds are usually normal between asthma episodes.

Tests may include:

Call your doctor if:

Call for an appointment with your health care provider if you or your child experience mild asthma symptoms (to discuss treatment options).

Call your health care provider (or go to the emergency room) for moderate shortness of breath (shortness of breath with talking, peak flow 50-80% of personal best), if symptoms worsen or do not improve with treatment, or an attack requires more medication than recommended in the prescription.

Go to the emergency room for severe shortness of breath (shortness of breath at rest, peak flow less than 50% of personal best), if drowsiness or confusion develops, or for severe chest pain.

Asthma treatment

Asthma treatment is aimed at avoiding known allergens and respiratory irritants, and controlling symptoms and airway inflammation through medication. The main goals are to restore normal airway function and prevent severe acute attacks.

Medication for asthma is either delivered by inhalation, orally or parenterally.

Inhalation is the preferred route of administration as this allows the drug to be delivered directly into the airways in smaller doses. This causes fewer side effects than if given systemically or parenterally. When delivered by inhalation, bronchodilators also have a faster onset of action and give better protection from bronchoconstriction.

Persons with mild asthma may use quick relief medication as needed. Those with persistent asthma should use preventative medicine on a regular basis to prevent asthma attacks. Medication is added in a step-up progression depending on the severity and frequency of attacks. It is also important to step-down the treatment when control is good.

There are two basic kinds of medication for the treatment of asthma.

  1. Long term control medications.
  2. Short acting medications.

Long-term control medications are also known as "preventers" and are used on a regular basis to prevent attacks. These are not appropriate as treatment during an attack. It includes inhaled corticosteroids, long acting bronchodilators, leukotriene inhibitors and mast cell stabilizers. Oral theophylline can also be used as a preventative in patients with chronic asthma, but isn't used as often as in the past.

Inhaled Corticosteroids

Inhaled corticosteroids prevent inflammation of the airways. It must be used regularly to get maximum benefit, and is recommended for prophylactic treatment of asthma when patients are using a beta2 agonist inhaler more than once daily.

Brand Name Generic Name
Aerobid, Aerospan HFA flunisolide
Alvesco ciclesonide
Asmanex Twisthaler mometasone
Azmacort triamcinolone
Flovent fluticasone
Pulmicort, (Discontinued - Rhinocort) budesonide
Qvar 40, Qvar 80 (Discontinued - Beclovent, Vanceril) beclomethasone

Long-Acting Beta2 Agonist Bronchodilators

Long-acting beta2 agonist bronchodilators relax muscles in the airways and improves breathing. These are used in conjunction with short acting beta2 agonists, which have faster onset of action. Although good asthma control may be established with long acting beta2 agonists, inhaled steroid therapy should not be discontinued. It may however reduce the need for continued high doses of inhaled corticosteroids, which cause unwanted side effects.

Brand Name Generic Name
Brovana (used mainly for COPD) arformoterol
Foradil formoterol
Serevent salmeterol

Leukotriene Inhibitors

Leukotriene inhibitors are oral medications, which work by blocking a substance called leukotriene. Leukotriene causes certain allergy symptoms and is associated with the inflammatory process in asthma.

Brand Name Generic Name
Accolate zafirlukast
Singulair montelukast
Zyflo (Discontinued) zileuton

Mast Cell Stabilisers

Mast cell stabilisers work by stabilizing mast cells and preventing them from releasing their irritating chemicals. Some forms of recurrent or chronic asthma are due to the release of irritating chemicals from mast cells located in the bronchial tubes.

Brand Name Generic Name
Intal cromolyn
Tilade nedocromil

Monoclonal Antibodies or Anti-IgE Therapy

Anti-IgE Therapy is an antibody that helps decrease allergic response in the body and is administered by injection to patients with severe asthma. It is usually given after other asthma medications have been unsuccessful.

Brand Name Generic Name
Xolair omalizumab

Methylxanthines

Methylxanthines are not used as often as in the past. They are given orally, rectally or intravenously. These are regarded more as relievers but oral theophylline may be given long term as well.

Theophylline has a narrow therapeutic index i.e. the level required for it to give therapeutic benefit is close to the toxic level. Patient should be monitored for serious toxic effects such as tachycardia and persistent vomiting. Once therapy is started and patient is stabilzed, the same theophylline preparation should be used. Care should also be taken when medicines, which interact with theophylline, are added or withdrawn.

Brand Name Generic Name
Truphylline (suppository) aminophylline
Elixophyllin, Theochron, Theolair, Uniphyl theophylline
Choledyl-SA oxtriphylline
Lufyllin dyphylline

Antimuscarinic Bronchodilators

Antimuscarinic bronchodilators block muscarinic receptors in the bronchial smooth muscle and cause bronchodilation. Compared to beta2 agonists, these have a slower onset of action but last longer. They may be useful if other therapy does not adequately control symptoms. These are used more in patients with chronic obstructive pulmonary disease (COPD).

Brand Name Generic Name
Spiriva tiotropium
Atrovent HFA ipratropium (short acting)

Oral bronchodilators such as albuterol, theophylline or aminophylline may be given long term, to patients who cannot use their inhalers properly.

Short Acting Medications are also known as "relievers". They are quick acting or rescue medications used to relieve symptoms during an attack. These include short acting beta2 agonists and corticosteroids.

Short-Acting Beta2 Agonist Bronchodilators

Short-acting beta2 agonists relax muscles in the airways and improve breathing. They have a faster onset and a shorter duration of action compared to the long acting beta2 agonist bronchodilators.

Brand Name Generic Name
Accuneb (Nebulizing Solution), Proair HFA, Proventil HFA, Ventolin HFA (Inhalers) Vospire ER (Oral), (Discontinued Volmax) albuterol
Alupent (Inhaler and Nebulizing Solution) metaproterenol
Terbutaline - Generic Only (Discontinued - Bricanyl, Brethine) terbutaline
Xopenex (Nebulizing Solution), Xopenex HFA (Inhaler) levalbuterol

Corticosteroids

Corticosteroids are given orally (short term) during asthma exacerbations or given intravenously during severe acute attacks.

Brand Name Generic Name
Prednisone, Prednisone Intensol prednisone
Flo-Pred, Orapred, Pediapred prednisolone
A-Methapred, Depo-Medrol, Medrol methylprednisolone
A-Hydrocort, Cortef hydrocortisone

Other Adrenoreceptor Agonists

Adrenoreceptor agonists such as ephedrine and metaproterenol are used less frequently than the selective beta2 agonists, as they are more likely to cause arrhythmias and other side effects. These should be avoided.

Brand Name Generic Name
Epipen, Twinject (Injection), Bronitin Mist, Primatene Mist (Inhalation) epinephrine
Ephedrine - Generic Only (Tabs & Elixir) ephedrine
Alupent (Tabs & Elixir) metaproterenol

An acute severe asthma attack requires medical evaluation and may require a hospital stay, oxygen, and intravenous medications (such as aminophylline, corticosteroids and/or short acting beta2 agonists).

Combination Inhalers

There are a few inhalers which have 2 types of medications for the treatment of asthma or COPD
Brand Name Generic Name
Advair Diskus fluticasone and salmeterol
Combivent, Duoneb albuterol and ipratropium
Symbicort budesonide and formoterol

Peak Flow Meter

A peak flow meter is a simple device, which can be used to measure lung volume. It can be used at home to help you by indicating an attack coming and to take appropriate action, sometimes even before any symptoms appear. If you are not monitoring asthma on a regular basis, an attack can take you by surprise.

Peak flow measurements can help show when medication is needed, or when other action needs to be taken. Peak flow values of 50-80% of an individual's personal best results indicate a moderate asthma attack, while values below 50% indicate a severe attack.

See Also:

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