Selected Summaries

Indian Pediatrics 2000;37: 1158-1159

Can Single Dose Intramuscular Dexamethasone Replace Five Day Oral Prednisolone 
Therapy in Mild to Moderate Asthma Cases?

Asthma affects 10% of children globally and is one of the most common chronic diseases of childhood. Despite an improved understanding of the pathophysiology and therapy of asthma, the morbidity and mortality of this disease continues to increase. Whereas, the mainstay of treatment in an emergency room remains inhaled beta-2 agonists, an early addition of steroids does modify the disease process and decreases its severity. Short courses of steroids are often prescribed to asthma patients at discharge, the compliance of which may decrease as the symptoms improve. In order to find a safe and effective single dose therapy, drugs like injectable methyl-prednisolone and dexamethasone acetate are considered.

A prospective, randomized and investigator blinded study was conducted in patients aged between 6 months to 7 years who required corticosteroids to treat mild to moderate asthma as out patients. The main objective was to evaluate whether single dose intramuscular dexamethasone is as effective as 5-day course of prednisolone. A total of 33 patients were randomized to receive either PO prednisolone in dose of 2 mg/kg/day for 5 days (n = 16) or intramuscular dexamethosone acetate in dose of 1.7 mg/kg/dose as a single shot. Investigator blinding was achieved in all but 4 patients. Asthma symptoms such as cough and wheez-ing were rated on 0-4 scale by parents and their final composite scores were rated on 0-8 scale. Patients with history of administration of steroids in previous 2 weeks, fever >101°F, documented infection and asthma needing hospitalization were excluded from the study. Both groups continued to receive inhaled beta 2 agonists 4-6 hourly. The outcome measures were change in asthma signs or symptoms (Clincial Asthma Score) from D1 through D5 of treatment, number of patients reaching baseline clinical status by D5, decrease in beta 2 agonists inhalation use and tolerance of corticosteroid medications (the parents assess-ment of personality score, clinical asthma score and tolerance score were confirmed by peripheral health worker). The pituitary-adrenal axis was assessed by urinary cortisol/creatinine ratio by standard methods on D14. Fourteen in dexamethasone group and 16 in oral prednisolone group completed their diaries. It was observed that both the groups improved clinically during the first five days (p <0.0001) and no significant difference in clinical asthma score was seen at any time during the study. None of the patients needed hospitalization. The side effects and complica-tions due to both drugs were insignificant. Three in PO steroid group missed 75% of dose and 4 in same group missed 1/3rd of the dose due to refusal to take medications due to taste. Most of the children and parents preferred an intramuscular single shot injection in lieu of 5 days oral steroid in future. Of 23 available urinary samples, no significant change in cortisol/creatinine ratio was noticed in two groups.

Since pathophysiology suggests that asthma is a chronic inflammatory disease of bronchial airways, steroids have a role in management of this disorder due to their anti-inflammatory action. Steroids can be used in oral, injectable or inhaler forms.

Although, this is not a double-blind study and relies on subjective scoring system, it addresses an important issue related to oral prednisolone; bad taste and compliance with 5-day drug therapy. The compliance is affected once symptoms start improving. Intramuscular dexamethasone acetate offers a single shot therapy in mild to moderate asthma in these not so compliant and finicky patients(1). It offers a cheapter alternative to equally effective but costlier methylprednisolone therapy. The long duration of action (1-3 weeks) suppresses inflamation for at least 2 weeks(2).

However, intramuscular single shot therapy may induce a sense of false security and confidence in patients, parents and the health care providers. These patients may not attend the follow up clinics and present in emergency rooms with acute severe asthma. Also, it would be unwise to use intramuscular dexamethasone in severe asthma in the emergency room. Further, the pituitary axis suppression follow-ing intramuscular dexamethasone acetate is expected to be more as compared to oral prednisolone therapy as admitted by authors themselves(3,4). In addition, since the action of dexamethasone lasts longer, these patients are at risk of severe diseases especially if they encounter highly infectious viral illnesses such as Varicella. Lastly, one should never under-estimate the fear of needle in pediatric patients who refuse to attend follow up clinics for fear of injections. The inherent risks of transmission of potentially serious infections also deserve consideration.

Though, an equally effective alternative to 5-day oral prednisolone therapy in treatment of mild to moderate asthma, intramuscular dexamethasone needs further evaluation with double blinded study on larger numbers. The study also should not be extrapolated for acute severe asthma patients.

Shishir Kumar Bhatnagar,
Senior Resident,
Kalawati Saran Children Hospital,
New Delhi 110 001, India.

1. Frey H, Norman D. Duration of action of depot corticosteroids. Pharmacologia Clinica 1970; 2: 109-112.

2. Chervinsky P. Treatment of seasonal allergic rhinitis with long acting steroid injections: A comparison of four preparations. Ann Allergy 1968; 26: 190-193.

3. Spiegel RJ, Oliff AI, Bruton J, Vigersky RA, Echelberger CK, Poplack DG. Adrenal suppression after short-term corticosteroid therapy. Lancet 1979; 1: 630-633.

4. Hedner P, Person G. Suppression of the hypothalamic-pituitary-adrenal axis after a single intramuscular injection of methylpredni-solone acetate. Ann Allergy 1981; 47: 176-179.