Medication Summary
Oral and inhaled medications are used for patients with stable emphysema to reduce dyspnea and improve exercise tolerance. Most of the medications used in emphysema treatment are directed at the 4 potentially reversible mechanisms of airflow limitation: (1) bronchial smooth muscle contraction, (2) bronchial mucosal congestion and edema, (3) airway inflammation, and (4) increased airway secretions.
Bronchodilators
Class Summary
These agents decrease muscle tone in both the small and large airways of the lungs, thereby increasing ventilation. This category includes beta-adrenergic agents, methylxanthines, and anticholinergics.
Albuterol (Proventil, Ventolin)
Albuterol is a beta2 agonist that relaxes bronchial smooth muscle by action on beta2 receptors, with little effect on cardiac muscle contractility. Most patients (even those who have no measurable increase in expiratory flow) benefit from treatment. Inhaled beta-agonists initially are prescribed as needed. Frequency may be increased. Institute a regular schedule in patients on anticholinergic drugs who remain symptomatic. Albuterol is available as liquid for nebulizer, MDIs, and dry-powder inhalers.
Metaproterenol (Alupent)
Metaproterenol relaxes bronchial smooth muscle by action on beta2 receptors, with little effect on cardiac muscle contractility. Most patients (even those who have no measurable increase in expiratory flow) benefit from treatment. Inhaled beta-agonists initially are prescribed as needed. Frequency may be increased. Institute a regular schedule in patients on anticholinergic drugs who remain symptomatic. Metaproterenol is available as liquid for nebulizer, MDIs, and dry-powder inhalers.
Levalbuterol (Xopenex)
Levalbuterol is used for the treatment or prevention of bronchospasm. It is a selective beta2-agonist agent. Albuterol is a racemic mixture, while levalbuterol contains only the active R-enantiomer of albuterol. The S-enantiomer does not bind to beta2-receptors, but it may be responsible for some adverse effects of racemic albuterol, including bronchial hyperreactivity and reduced pulmonary function during prolonged use.
Ipratropium (Atrovent)
Ipratropium is chemically related to atropine. It has antisecretory properties, and, when applied locally, it inhibits secretions from serous and seromucous glands lining the nasal mucosa. Ipratropium is used on a fixed schedule with a beta-agonist.
Salmeterol (Serevent)
By relaxing the smooth muscles of the bronchioles in conditions associated with bronchitis, emphysema, asthma, or bronchiectasis, salmeterol can relieve bronchospasm. The effect also may facilitate expectoration. Salmeterol may be useful when bronchodilators are used frequently. More studies are needed to establish the role for these agents. When administered at high or more frequent doses than recommended, the incidence of adverse effects is higher. The bronchodilating effect lasts longer than12 hours. It is used on a fixed schedule in addition to regular use of anticholinergic agents.
Formoterol (Oxis, Foradil)
Formoterol is currently not available in the United States (investigational beta-agonist with rapid onset and long duration of action). By relaxing the smooth muscles of the bronchioles in conditions associated with bronchitis, emphysema, asthma, or bronchiectasis, it can relieve bronchospasms. The effect also may facilitate expectoration. Formoterol has been shown to improve symptoms and morning peak flows in asthma. It may be useful when bronchodilators are used frequently. More studies are needed to establish the role for these agents. When administered at high or more frequent doses than recommended, the incidence of adverse effects is higher. The bronchodilating effect lasts longer than 12 hours. Formoterol is used on a fixed schedule in addition to regular use of anticholinergic agents.
Indacaterol, inhaled (Arcapta Neohaler)
Indacaterol is a long-acting beta2-agonist (LABA) indicated for long-term, once-daily maintenance bronchodilator treatment of airflow obstruction in patients with chronic obstructive pulmonary disease (COPD), including chronic bronchitis and/or emphysema. LABAs act locally in the lungs as bronchodilators. Indacaterol stimulates intracellular adenyl cyclase, causing conversion of ATP to cyclic AMP; increased cyclic AMP levels cause relaxation of bronchial smooth muscle. It is not for use as initial therapy in patients with acute deteriorating COPD.
Tiotropium (Spiriva)
Tiotropium is a quaternary ammonium compound. It elicits anticholinergic/antimuscarinic effects with inhibitory effects on M3 receptors on airway smooth muscles, leading to bronchodilation. It is available as a capsule dosage form containing a dry powder for oral inhalation via the HandiHaler inhalation device. It helps COPD patients by dilating narrowed airways and keeping them open for 24 hours.
Theophylline (Aminophylline, Theo-24, Theo-Dur, Slo-bid)
Theophylline potentiates exogenous catecholamines. It stimulates endogenous catecholamine release and diaphragmatic muscular relaxation, which stimulates bronchodilation. Its popularity has decreased because of its narrow therapeutic range and frequent toxicity. Bronchodilation may require near-toxic (>20 mg/dL) levels. However, clinical efficacy is controversial, especially in the acute setting. Theophylline has been shown to increase exercise capacity, decrease dyspnea, and improve gas exchange. A longer-acting agent is used daily or twice daily. The target concentration is 5-10 µg/mL. Dosing = (target concentration - current level) X 0.5 (ideal body weight). Alternatively, 1 mg/kg results in approximately a 2- µg/mL increase in serum levels.
Aclidinium (Tudorza Pressair)
Aclidinium is an M1-M3 muscarinic agonist (LAMA). It inhibits M3 receptors, leading to smooth muscle relaxation of bronchi; this leads to subsequent bronchodilation. Prevention of acetylcholine-induced bronchoconstriction effects were dose-dependent in in vitro and in vivo studies and lasted longer than 24 hours.
Corticosteroids
Class Summary
These agents attempt to moderate the inflammatory component of COPD. They should only be added to a regimen that includes a long-acting bronchodilator.
Fluticasone inhaled
Fluticasone inhaled has extremely potent vasoconstrictive and anti-inflammatory activity. It has weak inhibitory effects on the HPA axis when used at high doses for prolonged periods. Its effectiveness is not established in COPD.
Budesonide inhaled
Fluticasone inhaled has extremely potent vasoconstrictive and anti-inflammatory activity. It has weak inhibitory effects on the HPA axis when used at high doses for prolonged periods. Its effectiveness is not established in COPD.
Phosphodiesterase-4 Inhibitors
Class Summary
Selective phosphodiesterase-4 (PDE-4) inhibitors reduce exacerbations, improve dyspnea, and increase lung function in patients with severe COPD.
Roflumilast (Daliresp)
Roflumilast is a selective phosphodiesterase-4 (PDE-4) inhibitor. The specific mechanism of action is not well defined but is thought to be related to the effects of increased intracellular cyclic AMP in lung cells. It is indicated to decrease the frequency of exacerbations or the worsening of symptoms from severe COPD.
Smoking cessation therapies
Class Summary
These are most effective when used in conjunction with a support program (ie, counseling, group therapy, and behavioral therapy).
Bupropion is used as a non-nicotine aid to smoking cessation. One study demonstrated 23% sustained cessation with bupropion tablets at 1 year, compared with a 12% sustained cessation with placebo. Bupropion also may be effective in patients who do not quit with nicotine replacement therapy.
Varenicline (Chantix) is a partial agonist selective for alpha4, beta2 nicotinic acetylcholine receptors. It is used in conjunction with support groups and/or behavioral counseling. Gradually increase dose upward within 1 wk before quit date to 1 mg PO bid pc. Decrease dose with severe renal impairment or end-stage renal disease.
Nicotine transdermal system (Nicotrol, Habitrol, NicoDerm CQ)
Individuals who smoke more than 1 pack/d initially need a 21-mg patch followed by 14- and 7-mg patches.
Nicotine polacrilex (Nicorette)
Nicotine is absorbed through the oral mucosa. It is quickly absorbed and closely approximates the time course of plasma nicotine levels observed after cigarette smoking. It is available as 2- or 4-mg gum in a box containing 96 pieces. Careful adherence to chewing instructions is important for effective use. The manufacturer recommends that the gum not be used longer than 6 months. Individuals who smoke 1 pack/d should use 4-mg pieces. The 2-mg pieces are to be used by individuals who smoke less than 1 pack/d. Instruct patients to chew hourly and for initial cravings for 2 weeks, then gradually reduce the amount chewed over 3 months.
Bupropion (Zyban)
Bupropion is used in conjunction with a support group and/or behavioral counseling. It inhibits neuronal dopamine reuptake in addition to being a weak blocker of serotonin and norepinephrine reuptake.
Varenicline (Chantix)
Varenicline is a partial agonist selective for alpha4, beta2 nicotinic acetylcholine receptors. Its action is thought to be the result of activity at a nicotinic receptor subtype where its binding produces agonist activity, while simultaneously preventing nicotine binding. The agonistic activity is significantly lower than nicotine. It also elicits a moderate affinity for 5-HT3 receptors. Maximum plasma concentrations occur within 3-4 hours after oral administration. Following regular dosing, a steady state is reached within 4 days.
Antibiotics
Class Summary
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Amoxicillin (Amoxil, Trimox, Moxatag)
Amoxicillin interferes with the synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria
Doxycycline (Doryx, Monodox, Doxy, Adoxa)
Doxycycline is a broad-spectrum, synthetically derived bacteriostatic antibiotic in the tetracycline class. It is almost completely absorbed, concentrates in bile, and is excreted in urine and feces as a biologically active metabolite in high concentrations. It inhibits protein synthesis and, thus, bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. It may block dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Trimethoprim/sulfamethoxazole
Trimethoprim/sulfamethoxazole inhibits bacterial the synthesis of dihydrofolic acid by competing with para-aminobenzoic acid, resulting in inhibition of bacterial growth. The antibacterial activity of trimethoprim/sulfamethoxazole includes common urinary tract pathogens, except Pseudomonas aeruginosa. Like tetracycline, it has in vitro activity against Bartonella pertussis. It is not useful in mycoplasmal infections.
Azithromycin (Zithromax)
Azithromycin is replacing erythromycin as therapy for community-acquired pneumonia. It covers most potential etiologic agents, including Mycoplasma. The newer macrolides offer decreased GI upset and potential for improved compliance through reduced dosing frequency. They also afford improved action against Haemophilus influenzae.
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Emphysema. Gross pathology of bullous emphysema shows bullae on the surface of the lungs.
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Emphysema. Gross pathology of emphysema shows bullae on the lung surface.
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Emphysema. At high magnification, loss of airway walls and dilated airspaces are observed in emphysema.
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Emphysema. This chest radiograph shows hyperinflation, flattened diaphragms, increased retrosternal space, and hyperlucency of the lung parenchyma in emphysema.
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Emphysema. A computed tomography scan shows emphysematous bullae in the upper lobes.
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Emphysema. Diffuse emphysema secondary to cigarette smoking.
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Emphysema. A pressure-volume curve is drawn for a patient with restrictive lung disease and obstructive disease and is compared to healthy lungs.
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Emphysema. A flow-volume curve of lungs with emphysema shows a marked decrease in expiratory flows, hyperinflation, and air trapping (patient B) compared to a patient with restrictive lung disease, who has reduced lung volumes and preserved flows (patient A).
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Emphysema. Forced expiratory volume in 1 second (FEV1) can be used to evaluate the prognosis in patients with emphysema. The benefit of smoking cessation is shown here because the deterioration in lung function parallels that of a nonsmoker, even in late stages of the disease.
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Emphysema. A computed tomograph scan showing severe emphysema and bullous disease.
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Emphysema. An emphysematous lung shows an increased anteroposterior (AP) diameter, increased retrosternal airspace, and flattened diaphragms on posteroanterior (PA) film.
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Emphysema. An emphysematous lung shows an increased anteroposterior (AP) diameter, increased retrosternal airspace, and flattened diaphragms on a lateral chest radiograph.
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Emphysema. The differential diagnosis of a unilateral hyperlucent lung includes pulmonary arterial hypoplasia and Swyer-James syndrome. The expiratory chest radiograph exhibits evidence of air trapping and is helpful in making the diagnosis. Swyer-James syndrome is unilateral bronchiolitis obliterans, which develops during early childhood.
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Emphysema. A lateral chest radiograph of Swyer-James syndrome may demonstrate some of the features of emphysema.
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Emphysema. Paraseptal emphysema. Courtesy of Dr Frank Gaillard, Radiopaedia.org (http://radiopaedia.org/cases/emphysema-diagrams).
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Emphysema. Panlobular emphysema. Courtesy of Dr Frank Gaillard, Radiopaedia.org (http://radiopaedia.org/cases/emphysema-diagrams).
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Emphysema. Centrilobular emphysema. Courtesy of Dr Frank Gaillard, Radiopaedia.org (http://radiopaedia.org/cases/emphysema-diagrams).
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Emphysema. Early stethoscope drawing circa 1819. From Wikipedia.
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Emphysema. Laennec's early stethoscope made of brass and wood circa 1820. From Wikipedia.
