Relative efficacy of three different inhalers containing salbutamol in patients with asthma.
OBJECTIVE
To investigate the relative efficacy of three inhalers containing salbutamol: Turbuhaler (TBH), Rotahaler (RH) and Diskhaler (DH).


METHODS
A randomized, open, three-way crossover, cumulative dose response study was performed in 20 patients with asthma with mean forced expiratory volume in ls (FEV1) values of 60% of predicted (range 41-90%) and a 27% reversibility in FEV1 (range 15-61%). Four doses of salbutamol were inhaled at 30-min intervals: 50 micrograms, 50 micrograms, 100 micrograms and 200 micrograms by TBH and 200 micrograms, 200 micrograms, 400 micrograms and 800 micrograms by both RH and DH. FEV1 was measured at baseline and 25 min after each dose.


RESULTS
The increases in FEV1 after the first doses (50 micrograms by TBH, 200 micrograms by RH and by DH) were not statistically significantly different (23.6%, 25.1% and 28%, respectively). Based on the parallel shift in the dose response curves, salbutamol TBH was calculated to be 2.4 times as potent as salbutamol RH (95% confidence interval 1.4-3.3) and 2.2 times as potent as salbutamol DH (90% CI 1.3-3.3). Additionally, during dosing with TBH, fewer patients experienced adverse events than during dosing with RH or DH.


CONCLUSIONS
Turbuhaler is a twofold more efficient inhaler for salbutamol than Rotahaler or Diskhaler as measured by its bronchodilating effect.
Mahadewsingh
J V
JV
Onze Lieve Vrouwe Gasthuis, Department of Pulmonology, Amsterdam, The Netherlands.
Hamersma
W B
WB
Schreurs
A J
AJ
D000328:Adult; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage* / Q000009:adverse effects; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers
D001993:Bronchodilator Agents; D000420:Albuterol