Studies comparing short acting β agonists in combination with inhaled corticosteroids with inhaled corticosteroid alone
| Reference |
No. of patients | Study design | Results | Comments |
| Dahl et al 76 | 37 | DB, crossover, 3 weeks. Oral terbutaline/inhaled budesonide/both | Higher peak flows + fewer nocturnal awakenings with combination | Oral terbutaline used. Small differences between treatments |
| Bennati et al 77 | 30 | DB, parallel group, 1 month. Salbutamol/beclomethasone/both | PC20 (methacholine) higher after combination than beclomethasone alone (NS) | Salbutamol used prn in beclomethasone group. Small numbers of subjects |
| Selroos et al 78 | 12 | DB, crossover, 3 weeks. Terbutaline + budesonide/budesonide | FEV1 higher with combination. No difference in peak flow or PD20(histamine) | Abstract report. Small numbers of subjects |
| Wilding et al 79 | 16 | DB, crossover, 2 weeks. Terbutaline + budesonide/budesonide | Evening peak flow higher with combination. Morning peak flow also higher (NS). | Small differences only. Small numbers of subjects |
| Barnes et al 80 | 74 | DB, crossover, 4 weeks. Terbutaline/budesonide/ both | Peak flow higher with combination. Fewer symptoms with combination | Very low dose terbutaline used. β agonist used prn throughout |
| Hancox et al 81 | 61 | DB, placebo controlled, crossover, 6 weeks. With/without ipratropium used as supplement. Terbutaline/budesonide/ both/placebo | Combination 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 | 34 | DB, placebo controlled, crossover, 6 weeks. Ipratropium used as supplement. Terbutaline/budesonide/ both/placebo | BHR to hypertonic saline and sputum eosinophils increased with terbutaline | Pro-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.