Keeping It in Control: Managing Asthma in Children

Author: Monica Holmberg, PharmD

Over the past 20 years, the incidence of asthma in children aged 1 to 14 years has been steadily on the rise.1 Its prevalence worldwide ranges from 1% to 30%. Treatment options and monitoring can allow asthmatic patients to have fewer exacerbations, live active lives, and have nearly normal lung function.2

Asthma is a chronic inflammatory disorder of the airways that often presents as wheezing, breathlessness, chest tightness, and coughing. When exposed to triggers, the airways become blocked or narrowed from bronchoconstriction, mucus plugs, and increased inflammation. Although these asthma attacks or exacerbations occur periodically, the inflammation always is present. Additionally, the airways of patients with asthma become hyperresponsive?they respond to stimuli that might not produce respiratory distress in a nonasthmatic patient.1,2

The most objective measurement of asthma severity is assessment of lung function. Spirometry measures the forced expiratory volume in 1 second (FEV1). Spirometry is a good way to diagnose asthma and assess its reversibility after administration of a fast-acting bronchodilator medication. Peak expiratory flow (PEF) often is used in both the diagnosis and measurement of asthma control.2 Unfortunately, most children =5 years old are unable to perform pulmonary function tests, and thus the use of FEV1 or PEF in this age group is not recommended.1,2

Complicating matters further, making a diagnosis of asthma based on presentation alone frequently is difficult. Wheezing often is a major symptom leading to a diagnosis of asthma; however, in children <5 years of age, wheezing may be a symptom of respiratory conditions other than asthma.1,2 Despite the obstacles to diagnosis, successful asthma management is possible through early detection, appropriate pharmacologic treatment, and patient education.

Medications: Controllers Versus Relievers

Medications play a key role in the treatment of asthma. Two general classes categorize asthma medications: controllers and relievers. Controller medications are taken on a daily basis to prevent the occurrence of asthma exacerbations. Reliever medications are fast-acting medications that work quickly to open the airways during an exacerabation.2

Controllers

Systemic or inhaled glucocorticoids offer effective asthma control and usually are considered first-line treatment.2,3 They bind to a cytosolic receptor, which then impacts the cell nucleus to modulate gene expression, resulting in an antiinflammatory response.3 Examples of oral glucocorticoids include prednisone, methylprednisolone, and prednisolone. Examples of inhaled glucocorticoids include beclomethasone, budesonide, flunisolide, fluticasone, mometasone, and triamcinolone.2

Long-acting beta2 agonists are inhaled agents that keep airways open by binding to the beta2 receptor in the smooth muscle. Examples include salmeterol and formoterol.2

Inhaled cromolyn or nedocromil offers another option for controller therapy. These agents are believed to work by inhibiting degranulation of the mast cells, neutrophils, monocytes, and eosinophils and by possibly inhibiting immunoglobulin E production.3 Cromolyn and nedocromil usually are well-tolerated but often require a frequent dosing interval, which may impede adherence in some patients.2

Leukotriene inhibitors offer a controller medication in an oral formulation. Leukotrienes are produced by mast cells, alveolar macrophages, and eosinophils. They increase the vascular permeability of the lung to induce hyperresponsiveness and edema of the airway wall. Examples of leukotriene modifiers or antagonists include montelukast, zafirlukast, and zileuton.3

Xanthine derivatives relax the smooth muscle of the airway. These agents require monitoring of serum concentration, because higher concentrations can cause adverse effects including seizures, tachycardia, and arrhythmias. The most common oral xanthine derivative is sustained- release theophylline.2

Relievers

Reliever medications are available in both oral and inhaled formulations. The inhaled route often is preferred, because it has a faster onset of action and a lower incidence of side effects than the oral route.2 Short-acting beta2 agonists open the airways by binding to the beta2 receptor on the airway smooth muscle, causing an increase in adenylate cyclase and intracellular cyclic adenosine monophosphate.3 Side effects may include tachycardia, tremor, headache, and irritability. Popular inhaled short-acting beta2 agonists are albuterol, pirbuterol, and levalbuterol. Oral formulations include terbutaline and albuterol.2

Anticholinergic medications are available only in the inhaled formulations and often are used in conjunction with short-acting beta2 agonists or alone in patients who do not tolerate the short-acting beta2 agonists. The most commonly used anticholinergic medication is ipratropium.2

Stepwise Therapy

The stepwise approach offers guidelines for asthma management based on the patient's age and symptoms. All patients should have access to a short-acting beta2 agonist as needed for symptoms. Children =5 years old may require a nebulizer, face mask, spacer, or holding chamber (see sidebar: Getting Medications into Children). In some cases, oral beta2 agonists may be necessary. Treatment should be reviewed on a regular basis, with therapy adjustments based on the patient's improvement or decline.4

Step 4: Severe Persistent

Step 3: Moderate Persistent

Step 2: Mild Persistent

Step 1: Mild Intermittent

Patient Education

Pharmacists should counsel patients, family members, and caregivers to identify and avoid asthma triggers. Common irritants include animals with fur, temperature changes, aerosol chemicals, drugs, exercise, pollen, secondhand tobacco smoke, and viral respiratory infection.

Pharmacists should be sure that patients, family members, and caregivers understand the differences between controller and reliever medication and when to use each. They should emphasize the importance of continuing controller medications, even if asthma symptoms are no longer present (see sidebar: I Think I Need a Refill, but I'm Not Sure?).

If possible, chronic medication regimens should be simplified so that doses can be scheduled before or after school hours. Children with asthma may need written authorization from their physician to carry a reliever medication on school property and during school hours. It may be helpful for the school to have a written asthma action plan, which outlines medications to be given during exacerbations.5

Treating children for any chronic disease state requires extensive education of the child, family, caregivers, and school personnel. Asthma is a chronic condition, and, although there is no cure, asthma can be controlled through avoiding asthma triggers, appropriate medication use, and frequent monitoring.

Dr. Holmberg is a pharmacist with Phoenix Children's Hospital, Phoenix, Ariz.


References

1. Larsen G. Differences between adult and childhood asthma. J Allergy Clin Immunol. 2000;106(3 suppl):S153-S157.

2. Pocket Guide for Asthma Management and Prevention in Children. Global Initiative for Asthma. Available at: www.ginasthma.com/Guidelineitem.asp??l1=2&l2=1&intId=49. Accessed January 2007.

3. Whittaker L, Cohn L. Recent concepts in the pathogenesis and treatment of asthma. Clinical Pulmonary Medicine. 2002;9(3):135-144.

4. NAEPP Expert Panel Report. Available at: www.nhlbi.nih.gov/guidelines/asthma/execsumm.pdf. Accessed January 2007.

5. Practical Guide for the Diagnosis and Management of Asthma. Available at: www.nhlbi.nih.gov/health/prof/lung/asthma/practgde/practgde.pdf. Accessed January 2007.