Optimal starting dose of inhaled corticosteroids in adult asthma: why has it taken so long?

It is disturbing to realise that, although inhaled corticosteroids have been prescribed for over three decades in the treatment of asthma, there are still major therapeutic issues associated with their use that have yet to be clearly determined. One of these issues is the optimal starting dose. This uncertainty is illustrated by the different approaches that have been proposed for starting inhaled corticosteroids in patients with asthma ranging from “start with a high dose then step down once control has been achieved”,^1,2 “start with a dose of 400 µg³ or 200–500 µg per day beclomethasone dipropionate (BDP) or equivalent and then step up if required”,⁴ or “start at the dose considered to be appropriate for the severity of disease, usually 400 µg of BDP or equivalent”.⁵

To address this uncertainty and determine the optimal starting dose of inhaled corticosteroids in adults with asthma, Powell and Gibson have undertaken a systematic review and meta-analysis of randomised controlled trials that have investigated this issue. Their findings were reported in a recent issue of Thorax⁶ and indicate that, for patients with asthma who require inhaled corticosteroids, there is no evidence of a difference in efficacy between commencing with a moderate dose (400 µg per day BDP or equivalent) compared with a high dose (≥800 µg per day) and stepping down. An initial moderate dose of inhaled corticosteroids was more effective than an initial low dose (200 µg per day).

These findings are reassuring in that they do not support the “start high, step down” approach …