Table 2

Summary of trials comparing terbutaline delivered via Turbohaler (TBH) and via CFC-MDI

Ref.
no.		Patient numbers and characteristicsStudy designIntervention2-aDose of terbutaline
via CFC-MDI		Dose of terbutaline via TurbohalerOutcome measuresInterpretation of result
Efficacy2-bPotency
38 10 “stable” asthmaticsOpen crossover RSingle dose500 μg500 μgFEV1, VCTBH = CFC-MDI
39 46 asthmatic adultsOpen crossover RSingle dose on separate days250 μg, 500 μg250 μg, 500 μgFEV1, FVCTBH = CFC-MDITBH = CFC-MDI
40 10 highly reactive asthmatic adultsSB crossover R, PCSingle dose on separate days250 μg250 μgsGawTBH = CFC-MDI
41 13 moderately asthmatic adultsDB crossover RSingle dose on separate days250 μg, 500 μg250 μg, 500 μgFEV1, FVC, PEFR, FEF25–75%, sGawTBH = CFC-MDITBH = CFC-MDI
42 22 moderately asthmatic childrenOpen parallel RSingle dose500 μg (spacer device)500 μgFEV1, PEFR, sGawTBH = CFC-MDI
43 12 children (exercise-induced asthma)DB crossover R, PCSingle dose on separate days500 μg500 μgFEV1, VTG, VCTBH = CFC-MDI
44 118 mildly asthmatic childrenDB parallel R, PCSingle dose on separate days500 μg500 μgFEV1, Vmax50% TBH = CFC-MDI (FEV1)TBH = CFC-MDI
TBH > CFC-MDI (Vmax)
45 12 moderately asthmatic adultsDBSingle dose?? (spacer device)??FVC, FEV1, PEFR, FEF25–75% TBH = CFC-MDI
46 10 mildly asthmatic adultsDB crossover R, PCSingle dose on separate days1000 μg (spacer device)1000 μgFEV1 TBH = CFC-MDI
47 15 severe COPD adultsDB crossover R, PCSingle dose on separate days1.0 mg, 2.5 mg (spacer device)1.0 mg, 2.5 mgFEV1, FVC, RV, sGawTBH = CFC-MDI
48 15 mild to moderately asthmatic adultsDB crossover R, PCSingle dose on separate days2 mg (spacer device)1 mgFEV1 Not comparable
49 62 severely asthmatic childrenOpen parallel RSingle dose5 mg (spacer device)5 mgPEFR, FEV1 TBH = CFC-MDI
50 12 moderately asthmatic adultsOpen crossover RCumulative dosing250–4000 μg250–4000 μgFEV1, FVCTBH = CFC-MDITBH = CFC-MDI
51 9 moderately asthmatic adultsOpen crossover RCumulative dosing250–4000 μg250–4000 μgFEV1, FVCTBH = CFC-MDITBH = CFC-MDI
52 31 moderately asthmatic adultsOpen crossover RCumulative dosing125–4000 μg125–4000 μgFEV1, PEFR, FVC, FEF25–75% TBH = CFC-MDITBH = CFC-MDI
TBH > CFC-MDI (FEV1)
53 13 moderate to severely asthmatic childrenSB crossover RCumulative dosing125–1875 μg250–2000 μgFEV1, FVC, FEF25–75% TBH = CFC-MDITBH = CFC-MDI
54 10 asthmatic childrenDB crossover R, PCCumulative dosing250–2000 μg (spacer device)250–2000 μgRrsTBH = CFC-MDITBH = CFC-MDI
55 57 childrenDB crossover R2 weeks500 μg tid + prn500 μg tid+ prnPEFRTBH = CFC-MDI
56 19 moderately asthmatic adultsOpen crossover R2 weeks500 μg qid500 μg qidPEFRTBH = CFC-MDI
57 231 moderately asthmatic adultsOpen parallel R6 weeks500 μg qid500 μg qidPEFRTBH = CFC-MDI
58 21 childrenOpen crossover R2 weeks500 μg tid (spacer device)500 μg tidPEFR (am and pm)TBH > CFC-MDI (am)TBH ⩾ CFC-MDI
TBH = CFC-MDI (pm)

  • ↵2-a Time refers to duration of treatment per group.

  • ↵2-b Comparative efficacy at the doses used in each study.

  • SB = single blind; DB = double blind; R = randomised; PC = placebo controlled; VC = vital capacity; FVC = forced vital capacity; FEF25–75% = forced expiratory flow between 25% and 75% of FVC; Vmax50 = 50% maximum instantaneous forced expiratory flow; FRC = functional residual capacity; VTG = volume of trapped gas; Rrs = respiratory system resistance; sGaw = specific airway resistance; (=) = equieffective (or potent); more (>) and less (<) effective (potent); tending to be more (=) or less (=) effective (potent).