Table 1

Studies comparing short acting β agonists in combination with inhaled corticosteroids with inhaled corticosteroid alone

Reference No. of
Study design Results Comments
Dahl et al 76 37DB, crossover, 3 weeks. Oral   terbutaline/inhaled budesonide/bothHigher peak flows + fewer nocturnal   awakenings with combinationOral terbutaline used. Small differences   between treatments
Bennati et al 77 30DB, parallel group, 1 month.   Salbutamol/beclomethasone/bothPC20 (methacholine) higher after   combination than beclomethasone alone (NS)Salbutamol used prn in beclomethasone   group. Small numbers of subjects
Selroos et al 78 12DB, crossover, 3 weeks. Terbutaline +  budesonide/budesonideFEV1 higher with combination. No   difference in peak flow or PD20(histamine)Abstract report. Small numbers of subjects
Wilding et al 79 16DB, crossover, 2 weeks. Terbutaline +  budesonide/budesonideEvening peak flow higher with   combination. Morning peak flow also higher (NS).Small differences only. Small numbers of  subjects
Barnes et al 80 74DB, crossover, 4 weeks.   Terbutaline/budesonide/ bothPeak flow higher with combination. Fewer   symptoms with combinationVery low dose terbutaline used. β agonist  used prn throughout
Hancox et al 81 61DB, placebo controlled, crossover, 6   weeks. With/without ipratropium used as supplement. Terbutaline/budesonide/ both/placeboCombination treatment was highest   ranked. Morning peak flows higher with combination than sum of increments with single treatments.High doses of terbutaline used   (4000 μg/day) to maximise any possible adverse interaction.
Aldridge et al 63 34DB, placebo controlled, crossover, 6   weeks. Ipratropium used as supplement. Terbutaline/budesonide/ both/placeboBHR to hypertonic saline and sputum   eosinophils increased with terbutalinePro-inflammatory actions of terbutaline   not modified by combination of budesonide with terbutaline
  • DB = double blind; NS = not statistically significant; BHR = bronchial hyperresponsiveness; FEV1 = forced expiratory volume in one second; PD20 = provocative dose causing fall in FEV1 of 20% or more.