Single Dose Oral Dexamethasone Versus Multi-dose Prednisolone in the Treatment of Acute Exacerbations of Asthma in Children

Asthma is a major cause of pediatric morbidity and mortality. In acute exacerbations of asthma, corticosteroids reduce relapses, subsequent hospital admission and the need for ß2-agonist therapy. Prednisolone is relatively short-acting with a half-life of 12 to 36 hours, thereby requiring daily dosing. Prolonged treatment course, vomiting and a bitter taste may reduce patient compliance with prednisolone. Dexamethasone is a long-acting corticosteroid with a half-life of 36 to 72 hours. It is used frequently in children with croup and bacterial meningitis, and is well absorbed orally. The purpose of this trial is to examine whether a single dose of oral dexamethasone (0.3 mg/kg) is clinically non-inferior to prednisolone (1 mg/kg/day for three days) in the treatment of exacerbations of asthma in children who attend the Emergency Department.

This is a randomized, non-inferiority, open-label clinical trial. After informed consent with or without assent, patients will be randomized to either oral dexamethasone 0.3 mg/kg stat or prednisolone 1 mg/kg/day for three days. The primary outcome measure is the comparison between the Pediatric Respiratory Assessment Measure (PRAM) across both groups on Day 4. The PRAM score, a validated, responsive and reliable tool to determine asthma severity in children aged 2 to 16 years, will be performed by a clinician blinded to treatment allocation. Secondary outcomes include relapse, hospital admission and requirement for further steroid therapy. Data will be analyzed on an intention-to-treat and a per protocol basis. With a sample size of 232 subjects (105 in each group with an estimated 10% loss to follow-up), we will be able to reject the null hypothesis - that the population means of the experimental and control groups are equal with a power of 0.9. The Type I error probability associated with this test (of the null hypothesis) is 0.05.

This clinical trial may provide evidence that a shorter steroid course using dexamethasone can be used in the treatment of acute pediatric asthma, thus eliminating the issue of compliance to treatment.

Inclusion criteria

• Ages 2 to 16 years
• Background history of asthma as defined by at least one previous episode of ß2-agonist-responsive wheeze in a child two years of age or over or a prior diagnosis of asthma, made by a pediatrician, or clinician of comparable experience
• Presentation with an asthma exacerbation as defined as acute asthma, which prompts assessment at the ED, and has any, or all, of the following clinical features: Dyspnea, Wheeze, Acute cough, Increased work of breathing, Increased requirement for ß2-agonist from baseline use or O2 saturation <95%

Exclusion criteria

• Less than 2 years old or over 16 years
• Critical or life-threatening asthma (as defined below)
• Known TB exposure
• Active varicella or herpes simplex infection
• Documented concurrent infection with RSV
• Fever >39.5°C
• Use of oral corticosteroids in the previous four weeks
• Concurrent stridor
• Galactose intolerance, the Lapp-lactase deficiency or glucose-galactose malabsorption
• Significant co-morbid disease: lung, cardiac, immune, liver, endocrine, neurological or psychiatric