Respiratory Disease

Asthma, chronic obstructive pulmonary disease (COPD), and other respiratory conditions impose great hardship on hundreds of millions of patients around the world who suffer from these disease.

Asthma

Asthma is a chronic, debilitating respiratory condition with sudden, unpredictable and potentially life-threatening effects. Treatment requires constant vigilance and the active involvement of patients, families, physicians and other care-givers in a comprehensive programme to monitor, anticipate and promptly respond to the onset of asthmatic attacks.

Without effective and well tolerated treatment, people with asthma may be restricted in their physical activity, limited in their choice of work and afflicted by the side effects of some medications.
People with asthma experience a distressing set of symptoms:

The bronchial tubes are almost continuously inflamed and hyperreactive, sent into suffo-cating spasms by a broad range of provocations that may vary from one individual to another…An attack finds the victim gasping for breath as the airways become constricted, the passages inflamed and clogged with thick, sticky secretions.¹

Factors that may trigger asthma attacks include smoke, airborne moulds, pollens, dust, tiny scales from animal skin, exercise, cold air, household and industrial products, air pollutants, scents, and stress.

The incidence of asthma in developed countries is about 5-8 percent of the population, and at least 300 million people worldwide have the condition.²  It is estimated that 10-15% of children suffer from asthma.³

Asthma is increasingly common:

Data from many countries suggest that both asthma morbidity and mortality are increasing, although the reasons for this are not clear. Asthma prevalence has been reported to be increasing in the United States, the United Kingdom, New Zealand, and Australia; asthma mortality rates and mortality trends vary widely but appear to be increasing in many countries where data are available…⁴

Asthma is also a public health problem in developing countries: India has an estimated 15 to 20 million asthmatics.⁵   In Brazil, Costa Rica, Panama, Peru, and Uruguay, the prevalence of asthma is between 20 percent and 30 percent.⁶

The Management of Asthma

Asthma management guidelines categorize treatment in two ways: quick relief of symptoms and prevention of attacks.⁷

Quick relief of symptoms:

• Short-acting beta-agonists (e.g., salbutamol/ albuterol, pirbuterol, terbutaline) are bronchodilating medicines which have a fast onset of action to relax the smooth muscle of the airways.
  
  
• Other medicines for the relief of asthma symptoms include anticholinergic.
  
  
• Beta-agonists and anticholinergics are usually delivered via metered dose inhalers (MDIs).
  Prevention of attacks:
  
  
• Inhaled corticosteroid drugs are used as maintenance therapy for asthma to suppress the underlying inflammation and prevent congestion of the airways.
  
  
• Other medicines used in this area are long-acting beta-agonists, xanthines, leukothene modifying agents and non-steroid anti-inflammatories.
  
  
• Many drugs used in the prevention of attacks are delivered by MDIs.
  
  
• In severe asthma, additional amounts of steroids are administered as tablets or injections. However, long term therapy with this systemic administration is generally associated with some side effects.

Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary diseases such as emphysema and chronic bronchitis produce impaired airflow and poor lung function in patients. COPD is slowly progressive and generally irreversible, and severely restricts lung function.

The incidence of COPD is believed generally to be 8-15 percent of the population, at least in the developed world. For example, in the European Union, COPD and asthma rank together with pneumonia as the third most common cause of death. In the US, over 16 million people suffer from COPD.⁸   Deaths from COPD in the US rose from 53,000 in 1980 to nearly 96,000 in 1993.⁹

Risk factors associated with the development of COPD include:

• cigarette smoking
• recurrent infections
• pollution

Due to the slowly progressive nature of the disease and the influence of chronic exposure to irritants, COPD is a disease of the older population.

In an effort to relieve and prevent symptoms and improve breathing, COPD is treated with many of the same medicines as asthma (i.e., bronchodilator and anti-inflammatory agents). Since patients are prone to chest infection, some also require frequent courses of antibiotics.

¹ American Lung Association, Lung Disease Data 1996, at 3

² March 1996 Report of the Technology and Economic Assessment Panel, at 11.

³ National Heart, Lung, and Blood Institute, World Health Organization Report 1995.

⁴ National Heart, Lung, and Blood Institute, National Institutes of Health, International Consensus Report on Diagnosis and Management of Asthma, US Dept. of Health & Human Svcs. Pub. No. 92-3091, 28 (June 1992), at vii.

⁵ Statement by Dr. Nikoli Khaltaev, World Health Organization Expert (7 Dec. 1998 Press Release)

⁶ World Health Organization, "Bronchial Asthma" Factsheet No. 206 (Dec. 1998)

⁷ Global Initiative for Asthma. Pocket Guide for Asthma Management and Prevention - 1998.

⁸ N.M. Siafakas et al., "Optimal assessment and management of chronic obstructive pulmonary disease (COPD)," Consensus Statement of the European Respiratory Society (ERS). S Eur. Respir, 1, 1398, 1398 (1995).

⁹ American Lung Association, Lung Disease Data 1996, at 14.