G.C. Khilnani and Amit Banga
Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
Aerosol therapy has revolutionised thetreatment of several respiratory diseases including obstructive airway diseases. This form of therapy refers to delivery of the drug directly into the lower airways for either topical or systemiceffect. The greatest advantage of this from of therapy is the use of smaller doses and thus, minimal systemic adverse effects, besides giving a rapid response. Aerosol therapy is now also being used forsystemic delivery of certain medications, such as insulin. The particle size (expressed as mass median aerodynamic diameter) is of critical importance as the drug delivery depends on the same to amajor extent. Several devices such as metered dose inhaler (MDI), dry powder inhaler (DPI) and nebulisers are available. Each of these devices have advantages and disadvantages that needs to be understoodfor optimising the benefit. Aerosol therapy is also used in patients on mechanical ventilation for bronchodilator therapy, anti-inflammatory medication and at times for instillation of antibioticsand mucolytics. A knowledge of principles and applications of aerosol therapy is essential for its effective use in various conditions. [Indian J Chest Dis Allied Sci 2008; 50: 209-219]
Key words:Lung, Obstructive airway disease, Asthma, Bronchodilators, Aerosol therapy.
Aerosol therapy refers to the delivery of a drug to the body via the airways by delivering it in an aerosolisedform. Whereas the aerosolised drug may be intended for systemic use utilising the vast surface area for absorption provided by the respiratory tract, the overwhelming majority of the aerosols aremeant for topical use. Evidence of use of aerosol therapy has been found during the days of Hippocrates1 who utilised hot vapours for the management of respiratory diseases. However, the modern era of...