Keeping It in Control: Managing Asthma in Children

Over the past 20 years, the incidenceof asthma in childrenaged 1 to 14 years has beensteadily on the rise.¹ Its prevalenceworldwide ranges from 1% to 30%.Treatment options and monitoring canallow asthmatic patients to have fewerexacerbations, live active lives, and havenearly normal lung function.²

Asthma is a chronic inflammatory disorderof the airways that often presentsas wheezing, breathlessness, chest tightness,and coughing. When exposed totriggers, the airways become blocked ornarrowed from bronchoconstriction,mucus plugs, and increased inflammation.Although these asthma attacks orexacerbations occur periodically, theinflammation always is present. Additionally,the airways of patients withasthma become hyperresponsive?theyrespond to stimuli that might not producerespiratory distress in a nonasthmaticpatient.^1,2

The most objective measurement ofasthma severity is assessment of lungfunction. Spirometry measures theforced expiratory volume in 1 second(FEV¹). Spirometry is a good way to diagnoseasthma and assess its reversibilityafter administration of a fast-acting bronchodilatormedication. Peak expiratoryflow (PEF) often is used in both the diagnosisand measurement of asthma control.² Unfortunately, most children =5years old are unable to perform pulmonaryfunction tests, and thus the useof FEV1 or PEF in this age group is notrecommended.^1,2

Complicating matters further, makinga diagnosis of asthma based on presentationalone frequently is difficult.Wheezing often is a major symptomleading to a diagnosis of asthma; however,in children <5 years of age, wheezingmay be a symptom of respiratory conditionsother than asthma.^1,2 Despite theobstacles to diagnosis, successful asthmamanagement is possible throughearly detection, appropriate pharmacologictreatment, and patient education.

Medications: Controllers VersusRelievers

Medications play a key role in thetreatment of asthma. Two general classescategorize asthma medications: controllersand relievers. Controller medicationsare taken on a daily basis to preventthe occurrence of asthma exacerbations.Reliever medications are fast-actingmedications that work quickly to openthe airways during an exacerabation.²

Controllers

Systemic or inhaled glucocorticoidsoffer effective asthma control and usuallyare considered first-line treatment.^2,3They bind to a cytosolic receptor, whichthen impacts the cell nucleus to modulategene expression, resulting in an antiinflammatoryresponse.³ Examples oforal glucocorticoids include prednisone,methylprednisolone, and prednisolone.Examples of inhaled glucocorticoids includebeclomethasone, budesonide, flunisolide,fluticasone, mometasone, andtriamcinolone.²

Long-acting beta² agonists are inhaledagents that keep airways open by bindingto the beta² receptor in the smoothmuscle. Examples include salmeteroland formoterol.²

Inhaled cromolyn or nedocromil offersanother option for controller therapy.These agents are believed to work byinhibiting degranulation of the mast cells,neutrophils, monocytes, and eosinophilsand by possibly inhibiting immunoglobulinE production.³ Cromolyn and nedocromilusually are well-tolerated butoften require a frequent dosing interval,which may impede adherence in somepatients.²

Leukotriene inhibitors offer a controllermedication in an oral formulation.Leukotrienes are produced by mast cells,alveolar macrophages, and eosinophils.They increase the vascular permeabilityof the lung to induce hyperresponsivenessand edema of the airway wall.Examples of leukotriene modifiers orantagonists include montelukast, zafirlukast,and zileuton.³

Xanthine derivatives relax the smoothmuscle of the airway. These agents requiremonitoring of serum concentration,because higher concentrations cancause adverse effects including seizures,tachycardia, and arrhythmias. The mostcommon oral xanthine derivative is sustained-release theophylline.²

Relievers

Reliever medications are available inboth oral and inhaled formulations. Theinhaled route often is preferred, becauseit has a faster onset of action and a lowerincidence of side effects than the oralroute.² Short-acting beta² agonists openthe airways by binding to the beta²receptor on the airway smooth muscle,causing an increase in adenylate cyclaseand intracellular cyclic adenosine monophosphate.³ Side effects may includetachycardia, tremor, headache, and irritability.Popular inhaled short-actingbeta2 agonists are albuterol, pirbuterol,and levalbuterol. Oral formulations includeterbutaline and albuterol.²

Anticholinergic medications are availableonly in the inhaled formulations andoften are used in conjunction with short-actingbeta² agonists or alone in patientswho do not tolerate the short-acting beta²agonists. The most commonly used anticholinergicmedication is ipratropium.²

Stepwise Therapy

The stepwise approach offers guidelinesfor asthma management based onthe patient's age and symptoms. Allpatients should have access to a short-actingbeta² agonist as needed for symptoms.Children =5 years old may requirea nebulizer, face mask, spacer, or holdingchamber (see sidebar: Getting Medicationsinto Children). In some cases, oralbeta² agonists may be necessary.Treatment should be reviewed on a regularbasis, with therapy adjustmentsbased on the patient's improvement ordecline.⁴

Step 4: Severe Persistent

• Continual daytime symptoms forchildren =5 years old; PEF or FEV¹=60% for children >5 years
• Frequent nighttime symptoms forchildren =5 years old; PEF variability>30% for children >5 years
• Preferred daily treatment: high-doseinhaled corticosteroids withlong-acting inhaled beta² agonists;systemic corticosteroids added ifneeded

Step 3: Moderate Persistent

• Daily daytime symptoms for children=5 years old; PEF or FEV¹ between80% and 60% for children >5 years
• Nighttime symptoms occurring >1time/week for children =5 years old;PEF variability >30% for children >5years
• Preferred daily treatment: low-doseinhaled corticosteroids with long-actinginhaled beta² agonists ormedium-dose inhaled corticosteroidsfor children =5 years old; forchildren >5 years, low-to-medium-doseinhaled corticosteroids withlong-acting inhaled beta² agonists;additional options for children >5years: increasing inhaled corticosteroidsto medium-dose range oradding either a leukotriene modifieror theophylline to inhaled corticosteroids

Step 2: Mild Persistent

• Daytime symptoms occurring >2times/week but <1 time/day for children=5 years old; PEF or FEV¹ =80%for children >5 years
• Nighttime symptoms occurring >2times/month for children =5 yearsold; PEF variability between 20% and30% for children >5 years
• Preferred daily treatment: low-doseinhaled corticosteroids; alternativeoptions: a leukotriene modifier, cromolyn,nedocromil, or sustained-releasetheophylline

Step 1: Mild Intermittent

• Daily daytime symptoms =2 days perweek for children =5 years old; PEFor FEV¹ =80% for children >5 years
• Nighttime symptomsoccurring =2nights/month for children=5 years old;PEF variability <20%for children >5 years
• No daily medicationrequired; shortcourses of systemiccorticosteroids possiblyrequired forexacerbations⁴

Patient Education

Pharmacists shouldcounsel patients, familymembers, and caregiversto identify andavoid asthma triggers.Common irritants includeanimals with fur,temperature changes,aerosol chemicals, drugs,exercise, pollen, secondhandtobacco smoke,and viral respiratoryinfection.

Pharmacists should be sure thatpatients, family members, and caregiversunderstand the differencesbetween controller and reliever medicationand when to use each. They shouldemphasize the importance of continuingcontroller medications, even if asthmasymptoms are no longer present (seesidebar: I Think I Need a Refill, but I'mNot Sure?).

If possible, chronic medication regimensshould be simplified so that dosescan be scheduled before or after schoolhours. Children with asthma may needwritten authorization from their physicianto carry a reliever medication onschool property and during school hours.It may be helpful for the school to have awritten asthma action plan, which outlinesmedications to be given duringexacerbations.⁵

Treating children for any chronic diseasestate requires extensive educationof the child, family, caregivers, and schoolpersonnel. Asthma is a chronic condition,and, although there is no cure, asthmacan be controlled through avoiding asthmatriggers, appropriate medication use,and frequent monitoring.

Dr. Holmberg is a pharmacist withPhoenix 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 Initiativefor 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 January2007.