Prednisone Tops Inhaler for Severe Asthma in ER
Through spirometry, the researchers found that the lung function of children given oral prednisone improved an average of 18.9 percent within four hours. Inhaled fluticasone, however, improved lung function by only 9.4 percent in that same time.
The study, which appeared in the Sept. 7 New England Journal of Medicine, reported that 31 percent of the children who received fluticasone needed hospitalization within the first 15 days after the emergency-room visit. Only 10 percent of prednisone-treated children were hospitalized.
The researchers had sought to determine whether an inhaled corticosteroid might produce the same benefits as an oral one without exposing the children to the systemic effects of the drug.
Children in the prednisone group received a maximum of 60 mg of oral prednisone syrup at a dose of 2 mg/kg. Fluticasone was given as a single 2-mg dose administered through an inhaler and spacer with a mouthpiece. Each child in the prednisone group also used a placebo inhaler. Likewise, each child in the fluticasone group received a dose of placebo syrup.
The children who participated in the study sought treatment for acute asthma at the emergency room of Torontos Hospital for Sick Children between October 1995 and April 1999. Only children whose condition was evaluated in the presence of one of the two research nurses involved in the project were enrolled in the study.
The 2,805 emergency-room visits by children 5 to 17 years old with a diagnosis of asthma yielded 103 eligible study participants. Fifty-two children were randomly assigned to the fluticasone group and 51 to the prednisone group.
With the exception of sex, both groups had similar demographic and clinical characteristics. The prednisone group had about two boys for every girl, whereas the fluticasone group had an even distribution of boys and girls.
After randomization, all children were treated with 0.15 mg/kg of albuterol delivered through a jet nebulizer with a tight-fitting face mask. Prednisone or fluticasone was administered no more than 20 minutes after the bronchodilator was given.
The albuterol dose was repeated immediately after prednisone or fluticasone treatment and at 20, 40, 60, 80, and 140 minutes after treatment with the study drug. Each of the first three albuterol doses also contained 250 mcg of ipratropium bromide, a bronchodilator whose mechanism of action differs from that of albuterol.
The forced expiratory volume in one second, a measurement of lung function, was determined 20 minutes before treatment, just before drug therapy started, and at 60, 120, 180, and 240 minutes after treatment. Forty-eight children from each group completed this portion of the study.
During the four-hour evaluation, the lung function of each child in the prednisone group remained stable or improved. However, 25 percent of the children who received fluticasone had smaller forced-expiratory volumes over time.
Fluticasone users were significantly more likely than prednisone users to vomit or have tremors or to need intravenous rehydration.
Children who had used oral prednisone within seven days of the emergency-room visit were excluded from the study. The researchers also excluded children who took 1000 mcg or more of inhaled beclomethasone dipropionate or budesonide each day or 500 mcg/day of inhaled fluticasone. Children unable to breathe reliably into the spirometer were not eligible for the study.
Parents were asked to continue their childrens drug therapy at home for seven days, then bring the patients back to the hospital for clinical assessment and spirometry on the eighth day.
Only 13 children in the fluticasone group and 26 in the prednisone group completed the home phase of the study and returned to the emergency room. Thus, no meaningful statistical comparison could be made between the treatment groups after the children left the hospital. The researchers attributed this low participation to parental reluctance to bring a child back to the hospital.
Soon after publication of the study, the U.S. subsidiary of London-based Glaxo Wellcome PLC issued a press release noting that a national guideline issued in 1997 by the National Institutes of Health recommended oral corticosteroids, not inhaled ones, for the emergency-room treatment of severe acute exacerbations of asthma. The subsidiary also stated that the labeled indications for its fluticasone inhalation aerosol exclude use by children younger than 12.
Glaxo Wellcome Canada provided one of two grants for the Canadian study.