- CONDITION CENTERS
Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of chronic morbidity and mortality in the United States.1 Scientists from the World Health Organization (WHO) estimate that, in 15 years, COPD will rank fifth as a worldwide burden of disease.2 Guidelines from the American Thoracic Society,3 the European Respiratory Society,4 and the British Thoracic Society5 have been developed and utilized. The guidelines used in most American clinics and hospitals are derived from the collaboration of the US National Heart, Lung, and Blood Institute and WHO to form the Global Initiative for Chronic Obstructive Lung Disease (GOLD).6 The focus of this review is based on the updated 2004 GOLD guidelines.
COPD is characterized by irreversible airflow limitation that is progressive and is associated with an abnormal inflammatory response of the lungs to noxious gases or particles. The "gold standard" for COPD diagnosis is spirometry, because it is standardized, reproducible, and the most objective way of measuring airflow limitation. Spirometry measures the maximal volume of air forcibly exhaled from the point of maximal inhalation, also called "forced vital capacity" (FVC), and the volume of air exhaled during the first second of this maneuver, known as "forced expiratory volume in 1 second" (FEV1). Patients with COPD have a decline in both FVC and FEV1. The presence of a postbronchodilator FEV1 of <80% of the predicted value in combination with a ratio of FEV1/FVC of <70% confirms the diagnosis of COPD.
Classic symptoms of COPD include sputum production, cough, and shortness of breath. Chronic cough usually is the first symptom of COPD. It may initially be intermittent but later is present every day, and often throughout the day. Sputum production and chronic cough often precede the development of airflow limitation many years before a patient decides to visit a health care provider.
Classification of Severity/Risk Factors
COPD is classified into 5 stages based on pulmonary function as assessed by spirometry and symptoms (Table 1).6 Most patients with COPD usually are not diagnosed until the later stages, however, when the disease is more clinically apparent and moderately advanced.
Cigarette smoking is clearly the number-1 modifiable risk factor associated with COPD. The prevalence of COPD is highest in countries where cigarette smoking is most common. In the past, most studies indicated that COPD mortality and prevalence were more dominant in men than in women.7-10 Recent studies1,11 from developed countries, however, reveal that the prevalence is almost equal between men and women, most likely reflecting the changing patterns of smoking.
Other major risk factors include a rare but significant deficiency of alpha1-antitrypsin; airway hyperresponsiveness from other respiratory diseases such as asthma, occupational dust and chemicals, and indoor and outdoor pollution; and a history of respiratory infection during childhood. There is evidence that the risk of developing COPD is inversely related to socioeconomic status, although the reason is not clearly defined.
The components and goals for the effective management of COPD should be understood by both the clinician and the patient (Tables 2 and 3).6 The patient should be informed of both nonpharmacologic and pharmacologic treatments. Smoking cessation needs to be emphasized, utilizing the 5 strategies to help the patient quit (Table 4).12 Many studies show that nicotine replacement therapy in any form (nicotine patch, gum, nasal spray, sublingual tablet, lozenge, or inhaler) is effective in helping patients who are willing to quit smoking. The use of bupropion and nortriptyline also has produced long-term quit rates. Clonidine may be effective but is limited by its adverse effects.
Managing Stable COPD
COPD patients usually present with irreversible lung damage, because existing medications only alleviate symptoms of the disease. Therefore, it is vital to manage stable COPD with specific treatment approaches. The overall approach is based on the severity of the disease state. A stepwise table that links the severity of the disease state to both nonpharmacologic and pharmacologic therapies is shown in Table 5.6
Inhaled bronchodilators such as beta2-agonists (eg, Foradil, Proventil, Serevent) and anticholinergics (eg, Atrovent, Spiriva) are the cornerstone of COPD pharmacotherapy. Despite higher cost, evidence-based trials have found long-acting bronchodilators to be more effective and convenient than short-acting bronchodilators.6 Theophylline also is effective as a bronchodilator in COPD. Because it must be administered systemically, however, inhaled therapy is more favorable due to less adverse effects. Combining bronchodilators will allow for maximal efficacy with minimal side effects.
Inhaled corticosteroids (eg, AeroBid, Azmacort, Flovent, Pulmicort) should be reserved only for patients with stage 3 or 4 COPD. If an inhaled corticosteroid is indicated, it is important to utilize it in conjunction with long-acting beta2-agonists. Chronic treatment utilizing systemic corticosteroids should be avoided regardless of severity. Studies also have found that patients with stage 4 COPD benefit from long-term administration of oxygen (>15 hours per day).
Other pharmacologic treatments include annual or biannual influenza vaccines and a pneumococcal vaccine every 5 years. Younger patients with severe hereditary alpha1-antitrypsin deficiency may consider alpha1-antitrypsin augmentation therapy. Antibiotics are not indicated in COPD unless there is clear evidence of bacterial infection.
There are 3 types of surgical treatments: bullectomy, lung volume reduction surgery, and lung transplantation. All 3 treatments are highly expensive and are not recommended for widespread use.
COPD exacerbations are mainly triggered by respiratory infection or air pollution. The mainstays of COPD exacerbation management include inhaled beta2-agonists and anticholinergics, as well as corticosteroids and theophylline. For patients with clinical signs of airway infection (including worsening dyspnea, cough, and increased sputum volume), antibiotic treatment may be beneficial. The antibiotic chosen should be effective against Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae. Furthermore, it is believed that noninvasive intermittent positive pressure ventilation improves respiratory imbalances and decreases hospital stay time.
COPD exacerbation can be managed either at home or in the hospital. For home management, patients are educated on how to increase the dose and frequency of their bronchodilators. A rescue vial containing corticosteroid tablets may be ordered for the patient to keep in case of emergencies, to help restore lung function and shorten recovery time. A dose of 30 to 40 mg of prednisolone daily for 10 to 14 days is recommended by the GOLD panel consensus judgment.6
COPD exacerbation occurring in the hospital setting usually is more severe and should be treated first with controlled oxygen therapy, followed by a combination of beta2-agonists and anticholinergics via a spacer or nebulization. Patients should be administered systemic corticosteroids. The addition of intravenous aminophylline may be considered, if needed.
COPD is a very prevalent disease state that may lead to severe morbidity and mortality. Several guidelines have been published worldwide, with GOLD being the most recognized in the United States. Classic symptoms of COPD include sputum production, cough, and dyspnea, and the diagnosis can be confirmed by using spirometry. Smoking is the number-1 modifiable risk factor, and cessation should be emphasized at each and every visit to a health care provider. In addition to smoking cessation, management of COPD includes vaccination, bronchodilators, corticosteroids, and oxygen. Pharmacists are responsible for ensuring optimal patient care by keeping up-to-date with current treatment standards.
Dr. Pham is an assistant professor of pharmacy practice at Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University.
For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. A. Stahl, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: firstname.lastname@example.org.