Recent advances in aerosol therapy for children with asthma

Inhalational drug delivery is the primary mode of asthma therapy in children and is the main focus of this article. Pressurized metered dose inhalers (pMDIs) are now the method of choice in infants and children under 5 years old, when used in combination with an appropriate valved holding chamber or spacer. Spacers are particularly important for steroid inhalation to maximize lung deposition and minimize unwanted oropharyngeal deposition. Optimal inhalation technique with a pMDI-spacer in infants is to inhale the drug by breathing tidally through the spacer. Drug delivery to the lungs using pMDIs can vary greatly, depending on the formulation used and the age of the child. Dry powder inhalers (DPIs) are driven by the peak inspiratory flow of the patient and are usually not appropriate for children under 5 or 6 years of age. Nebulizers continue to play a role in the treatment of acute asthma where high doses of bronchodilator are required, though multiple doses via pMDI spacer may suffice. Important drug delivery issues specific to children include compliance, use of mask versus mouthpiece, lower tidal volumes and inspiratory flows, determination of appropriate dosages, and minimization of adverse local and systemic effects.