According to asthma guidelines inhaled corticosteroids should be used for patients with all degrees of persistent asthma: mild, moderate and severe (1).
Controlled clinical trials have shown that treatment with Pulmicort (inhaled budesonide) reduces the degree of airway inflammation (airway biopsy studies), reduces the number of eosinophils in sputum and bronchoalveolar lavage fluid and reduces the non-specific bronchial hyperresponsiveness. By doing all these the patients experience
a) less day- and night-time symptoms,
b) less need of reliever medication,
c) improved exercise tolerance, and they have
d) an improved airway function, and
e) an improved asthma control and fewer exacerbations.
Most of the clinical efficacy is achieved with rather low doses of Pulmicort, as the dose-response curve for clinical efficacy is rather flat (2,3). However, statistically significant dose-response relationships have been demonstrated for most of the asthma variables (2,3). To demonstrate significant differences between treatments a factor of four has to be used between studied doses of Pulmicort, e.g. 100 µg vs 400 µg, or 400 µg vs 1600 µg (2).
Most patients with persistent asthma have a mild disease and can be treated with low doses of Pulmicort (< 400 µg per day). However, patients with a severe disease usually benefit more from a higher dose.
A good clinical approach from a practical point of view is often to start treatment with a medium high dose of Pulmicort Turbuhaler, e.g. 400 µg twice daily in adults, and to adjust the dose up or down depending on the clinical response.
Asthma of different degrees of severity will be discussed in detail below.
References:
1. From the Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA) 2007. Available from: http://www.ginasthma.org.
2. Busse WW, Chervinsky P, Condemi J, et al.: Budesonide delivered by Turbuhaler is efficive in a dose-dependent fashion when used in the treatment of adult patients with chronic asthma. J Allergy Clin Immunol 1998; 101: 457-463.
3. Miyamoto T, Takahashi T, Nakajima, S. et al.: Efficacy of budesonide Turbuhaler compared with that of beclomethasone dipropionate pMDI in Japanese patients with moderately severe asthma. Respirology 2001; 6: 27-35.
