TREATMENT OF CHRONIC OBSTRUCTIVE
PULMONARY DISEASE (COPD)
is characterized by airflow limitation that is not fully reversible with
bronchodilator treatment. The airflow limitation is usually progressive and is
believed to reflect an abnormal inflammatory response of the lung to noxious
particles or gases.
condition is most often a consequence of prolonged habitual cigarette smoking,
but approximately 15% of cases occur in nonsmokers. Although COPD is different
from asthma, some of the same drugs are used in its treatment. This section
discusses the drugs that are useful in both conditions.
asthma and COPD are both characterized by airway inflammation, reduction in
maximum expiratory flow, and epi-sodic exacerbations of airflow obstruction,
most often triggered by viral respiratory infection, they differ in many
important respects. Most important among them are differences in the
populations affected, characteristics of airway inflammation, reversibility of
airflow obstruction, responsiveness to corticosteroid treatment, and course and
prognosis. Compared to asthma, COPD occurs in older patients, is associated with
neutrophilic rather than eosino-philic inflammation, is poorly responsive even
to high-dose inhaled corticosteroid therapy, and is associated with
progressive, inexorable loss of pulmonary function over time, especially with
continued cigarette smoking.
Despite these differences, the approaches to treatment are similar, although the benefits expected (and achieved) are less for COPD than for asthma. For relief of acute symptoms, inhalation of a short-acting β agonist (eg, albuterol), of an anticholinergic drug (eg, ipratropium bromide), or of the two in combination is usually effective. For patients with persistent symptoms of exer-tional dyspnea and limitation of activities, regular use of a long-acting bronchodilator, whether a long-acting β agonist (eg, salmeterol) or a long-acting anticholinergic (eg, tiotropium) is indicated. For patients with severe airflow obstruction or with a history of prior exacerbations, regular use of an inhaled cortico-steroid reduces the frequency of future exacerbations. Theophylline may have a particular place in the treatment of COPD, as it may improve contractile function of the diaphragm, thus improving ventilatory capacity. The major difference in treatment of these conditions centers on management of exacerbations. The use of antibiotics in this context is routine in COPD, because such exac-erbations involve bacterial infection of the lower airways far more often in COPD than in asthma.