Aim: The effectiveness of the fully subsidised bronchodilator in New Zealand, Salamol, has recently been questioned. We compared the efficacy of Salamol and Ventolin inhalers in relieving acute bronchospasm. We also tested the efficacy of partially used Salamol inhalers because of concerns that the device may become blocked during use.
Methods: 12 asthmatic subjects were enrolled in this randomised, single-blind, 3-way crossover study. Subjects inhaled methacholine to produce a 20% fall in forced expiratory volume at 1 second (FEV1) on 3 different days. Salbutamol was given post-bronchoconstriction as Ventolin, Salamol (new), or Salamol (used) in random order. Inhalations of 100, 100, and 200 mcg salbutamol were delivered at 5 minute intervals via spacer and FEV1 was measured 5 minutes after each dose. The main outcome variable was the area under the salbutamol dose response curve.
Results: There was no significant difference in the bronchodilator response to salbutamol whether delivered as Ventolin or Salamol (p=0.63). Furthermore, there was no difference in bronchodilator response between used Salamol inhalers and new Salamol inhalers (p=0.60) or between used Salamol inhalers and Ventolin (p=0.08). The final FEV1s at 15 minutes (after a total of 400mcg salbutamol) were also similar for the different inhalers.
Conclusions: We found no evidence that either new or partially used Salamol inhalers are less effective at relieving acute bronchoconstriction than Ventolin.