Chronic obstructive pulmonary disease administration routes

Aminophylline is used in the treatment of asthma (as a bronchodilator) and in chronic obstructive pulmonary disease. In acute bronchospasm, aminophylline should not be given by the intravenous route the oral route is preferred. Parenteral administration can cause pain and is not recommended. Aminophylline is used as a cosmetic to remove fat from the thigh.45... 

Inhalation Inhalation provides the rapid delivery of a drug across the large surface area of the mucous membranes of the respiratory tract and pulmonary epithelium, producing an effect almost as rapidly as by intravenous injection. This route of administration is used for drugs that are gases (for example, some anesthetics), or those that can be dispersed in an aerosol. The route is particularly effective and convenient for patients with respiratory complaints (for example, asthma or chronic obstructive pulmonary disease) as drug is delivered directly to the site of action and systemic side effects are minimized (see p. 219). 

Pulmonary delivery of drugs is the administration route of choice in respiratory diseases such as chronic obstructive pulmonary disease and asthma. Different devices are available, including metered-dose inhalers, dry powder inhalers, and nebulizers, and nearly 80% of asthmatic patients worldwide use metered dose inhalers (1). Chlorofluorocarbons have been used as an aerosol propellant in metered-dose inhalers however, they deplete the ozone layer and are being replaced by more environment-friendly propellants, even though the contribution of aerosols of this type to the total global burden of chlorofluorocarbons is less than 0.5%. The first chloro-fluorocarbon-free metered-dose inhaler for asthma treatment was approved by the FDA in 1996 (2) and the European Union has set 2005 as a target date for the withdrawal of all chlorofluorocarbon-based inhalers (1). In the USA, prescriptions for chlorofluorocarbon-free medications rose from 16.4 million in 1996 to 33.8 million in 2000 (2). Most of the chlorofluorocarbon-free medications were steroids for nasal use (27.2 million). However, chlorofluorocarbon-containing medications stiU represented two-thirds of all prescriptions and increased from 63.0 to 67.6 million dispensed (2). 

The risk of severe, possibly even fatal bronchospasm when beta blockers are taken by asthmatics would seem to be far more important than any pharmacokinetic interaction with theophylline. See the warning in Anti-asthma drugs + Beta blockers , p.ll60. Therefore the non-cardioselective beta blockers, such as propranolol, are contraindicated in patients with asthma or chronic obstructive pulmonary disease (COPD). Bronchospasm can occur with beta blockers given by any route of administration, even topically as eye drops. Cardioselective beta blockers have less effect on the airways, but can still cause bronchoconstriction. See Table 22.1 , (p.833), for details of the selectivity of beta blockers. 

Pulmonary administration of medicines currently has the primary objective to achieve local effects in the respiratory tract of patients with chronic diseases like asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). For half a century, inhalation therapy has been the cornerstone in the management of these diseases and the often life-time therapies aim to suppress inflammatory processes and bacterial infection in order to reduce hospitalisations and to improve the patient s quality of life. They also give relief to the patient in moments of bronchoconstriction. The advantages of pulmonary administration of medicines for local treatment are well known. The active substances are delivered directly to the site of action which leads to a faster response than via the systemic route. It may also result in higher local active substance concentrations and this could reduce the total dose by as much as a factor 10 compared to oral or intravenous administration. This has the advantage that systemic side effects are reduced and in combination with being a non-invasive method of administration, inhalation therapy may lead to better patient compliance. 

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