The aim of our study was to evaluate the effect of age on lung deposition of radiolabelled budesonide, delivered as a dry powder via Turbuhaler to asthmatic children. A group of 23 asthmatic children, aged 6 to 16 years, with relatively stable asthma inhaled 99mTc-labelled budesonide from a dry powder inhaler (Turbuhaler). Body and lung deposition was assessed using a gamma camera. The mean (range) median peak inspiratory flow during inhalation was 65 1 x min(-1) (45 to 76 1 x min(-1)). Mean (range) total lung deposition of 99mTc-labelled budesonide, expressed as a percentage of the metered dose, was 29.1% (15.6-47.2%) and was positively and significantly correlated with age, height and peak inspiratory flow.
Conclusion: Total lung deposition of radiolabelled budesonide from a dry powder inhaler (Turbuhaler), is age dependent in children with moderate asthma. However, lung deposition is still satisfactory, even in younger children with lower peak inspiratory flows.