ECFS 2020 - Optimizing pharmaceutical care in cystic fibrosis

European Cystic Fibrosis Society   119  CHAPTER 7 Aerosol therapy for CF lung disease: the basics Authors Hettie M. Janssens, Harm A.W.M. Tiddens Introduction Aerosol treatment plays an important role in the treatment of lung disease for most patients with cystic fibrosis (CF). This treatment starts early in life and is continued throughout life. A large variety of therapies are delivered as an aerosol, including mucolytics, antibiotics, bron- chodilators, oligonucleotides, and gene therapy. A similarly wide array of aerosol delivery devices are used to deliver these therapies, ranging from nebulizers to dry powder inhalers (DPIs) and pressurized metered dose inhalers (pMDIs). The general view is that aerosol therapies provide high concentrations throughout the airways. In reality however, many factors determine the aerosol distribution in the lungs of CF patients, and concentrations vary widely throughout the bronchial tree. In order to optimize aerosol therapy from infancy into adulthood, prescribers of CF medication must have an in-depth understanding of the ins and outs of aerosol therapy. In this chapter we first cover the basics of aerosol therapies, and then discuss the various aerosol delivery devices. 1 The target area CF lung disease results in abnormal secre- tions in the lung that foster infection and inflammation [1, 2]. The vicious cycle of infection, inflammation, and thick pulmo- nary secretions leads to early structural lung damage. In addition to bronchiectasis, small airway disease plays an important role in CF lung disease [3]. In advanced lung disease the geometrical changes associated with small airway disease are significantly more severe than alterations affecting large airways. Progressive bronchiectasis and small airway disease eventually lead to end-stage lung disease [4]. The severity and distribution of the structural changes, in addition to mucus in the airways, all have a considerable impact on the distribution of inhaled aerosols. When prescribing aerosol therapy, it is therefore crucial to take these patient-specific structural changes into account. The most direct and sensitive means of visualizing these changes is chest computed tomography (CT) [5]. Another important issue to take into account when treating the airways is that the combined surface area of all small airways is in the range of several square meters. In general, drug inhalation results in very high concen-