Chronic obstructive pulmonary disease medical therapy: Difference between revisions
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* Worsening respiratory acidosis (pH < 7.30) | * Worsening respiratory acidosis (pH < 7.30) | ||
==Trial supportive data== | |||
Use of long acting anticholinergics like Tiotropium have shown a reduction in frequency of COPD exacerbations, hospitalization and improvement in quality of life when compared with placebo. However, these drugs didn't show any improvement in FEV1 or mortality benefits. Additionally, two recently conducted large randomized trials compared tiotropium (anticholinergics) with salmeterol (long acting beta agonist)and placebo. Both the studies showed increased benefits in lung function tests, symptoms and quality of life with tiotropium when compared to salmeterol. Other studies showed tiotropium to decrease the number of exacerbation when compared with salmeterol. | |||
==External link== | ==External link== |
Revision as of 14:21, 21 March 2012
Chronic obstructive pulmonary disease Microchapters |
Differentiating Chronic obstructive pulmonary disease from other Diseases |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Philip Marcus, M.D., M.P.H. [2]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [3]
Overview
Treatment of COPD requires a careful and thorough evaluation by a physician. The most important aspect of treatment is avoiding tobacco smoke and removing other air pollutants from the patient’s home or workplace. Symptoms such as coughing or wheezing can be treated with bronchodilator medications like Beta 2 receptor agonist, anticholinergic drugs. The drugs used cause benefit via relaxation of smooth muscle or decreasing inflammatory factors. . Respiratory infections should be treated with antibiotics, if appropriate. Patients who have low blood oxygen levels in their blood are often given supplemental oxygen. Currently, no treatment has been found to be totally curative against COPD except lung transplant. The treatments aim to improve lung function and quality of life. The initial treatment can be done either with Beta 2 agonist or anticholinergic. Both anticholinergics or Beta adrenergic receptor agonists have proved to be equally beneficial but the combination of the two has shown synergistic effects. Long acting bronchodilators are more beneficial than short-acting ones [1], [2].
Goal of treatment
- Improve symptoms
- Reduce exacerbation
- Improve quality of life
- Improve a patient's functional capacity
General therapy
- Patient education session about the disease, a self-treatment plan for exacerbations, and a monthly follow-up call from hospital or nurse practitioner , is associated with a lower hospitalization rate and fewer emergency department visits [3], [4]
- Treatment of COPD requires a careful and thorough evaluation by a physician.
- The most important aspect of treatment is avoiding tobacco smoke and removing other air pollutants from the patient’s home or workplace.
- Patients who have low blood oxygen levels in their blood are often given supplemental oxygen.
- Oral and inhaled medications are used for patients with stable chronic obstructive pulmonary disease (COPD) to reduce dyspnea, improve exercise tolerance, and prevent complications. Symptoms such as coughing or wheezing can be treated with bronchodilators like subcutaneous medications, beta-adrenergics, methylxanthines, and anticholinergics. They act via decreasing muscle tone in small and large airways in the lungs.
- Respiratory infections should be treated with antibiotics, if appropriate.
- Nutritional support forms an integral part of management for COPD patients.
Drug therapy
Route of therapy
- Inhaled delivery is preferred over the oral route as there is less systemic absorption via inhaled route thus less adverse effects. However, some patients may have difficulty achieving effective delivery of the medication using a metered-dose inhaler. Use of spacer or nebulizer may be beneficial in them.
Beta adrenergic receptor agonists
Short acting selective B2 agonist
- Used for symptomatic relief during acute mild, exacerbation
- Mechanism of action - Increases intracellular cyclic adenosine monophosphate via activation of B2 -adrenergic receptors on smooth muscle cells of airway and causes smooth muscle relaxation.
- These agents are less effective in COPD compared to Asthma
- Patients may not have increase in peak flows with treatment. However, it should be continued as it offers symptomatic relief.
- The inhaled route is preferred as there is less systemic absorption thus less side-effects.
- The adverse effects include tachycardia, tremors and cardiac arrhythmia.
- Drugs available are:
Albuterol, Metaproterenol, Pirbuterol
- Used for bronchospasm refractory to epinephrine.
- Route - Inhaled
Levalbuterol
- Albuterol is a racemic mixture containing both R and S enantiomer. The S enantiomer doesn't bind to Beta 2 receptor and maybe the cause of side-effects. On the other hand, levalbuterol has only active R enantiomer thus causes less side-effects.
- It is used for both treatment and prevention of bronchospasm.
Long acting beta-2 adrenergic receptor agonist
- The long acting beta 2 receptor agonist are used to alleviate chronic persistent symptoms
- They help to increase exercise tolerance, prevent nocturnal dyspnea, and improve quality of life.
- Long-acting beta-agonists include salmeterol, formoterol, arformoterol, and indacaterol.
- They all require twice-daily dosing, except for indacaterol. Bronchodilating effect lasts more than 12 hours. Indacaterol is administered once daily.
Salmeterol, Formoterol, Arformoterol
- Relieve bronchospasms.
- Facilitate expectoration, improve symptoms and morning peak flows.
- Used in addition to anticholinergic agents.
Arformoterol
- Higher potency than racemic formoterol.
Indacaterol
- Indacaterol a long-acting beta2-agonist (LABA) is used for long-term, once-daily maintenance in patients with chronic obstructive pulmonary disease (COPD) [5].
- It is not for use as initial therapy in patients with acute deteriorating COPD.
Anticholinergics
- Anticholinergic drugs act as a competitive inhibitor of acetylcholine and block their action on postganglionic muscarinic receptors, thus inhibiting cholinergically mediated bronchspasm and resulting in bronchodilatation.
- They block vagally mediated reflex arcs that cause bronchoconstriction.
- Reported adverse effects include dry mouth, metallic taste, and prostatic symptoms. Studies have found an increased incidence of acute urinary retention in patient above 66 years using inhaled anticholinergic medications than in nonusers [6].
Ipratropium
- They have similar efficacy as beta 2 adrenergic receptor agonist.
- They have a synergistic effect on broncho-dilatation when combined with beta 2 agonist.
- They have a slower onset and longer duration of action. Thus, lesser helpful in use on an as-needed basis.
- Dose - 2-4 puffs at 6-8 hour duration.
Tiotropium
- It is the only long-acting muscarinic (once daily) anti-cholinergic agent available at this time
- It has become a first-line therapy in patients with persistent symptoms.
- It is more effective than salmeterol in preventing exacerbation [7]
Xanthine derivatives
Theophylline
- Causes inhibition of enzyme phosphodiesterase that in turn increases cyclic adenosine monophosphate (cAMP), causing the relaxation of bronchial smooth muscles.
- It is mostly used as an adjunctive agent and reserved in non-responsive patients or patients having difficulty in using inhaled agents.
- It has a narrow therapeutic index and adverse effects, like anxiety, tremors, insomnia, nausea, cardiac arrhythmia (multifocal atrial tachycardia), and seizures above the therapeutics range. Previously the recommended target range was 15-20 mg/dL. However, now it has been reduced to 8-13 mg/dL.
- It is metabolized via cytochrome P 450 system. Thus, the plasma concentration of theophylline is affected by age, cardiac status, and liver abnormalities.
Phosphodiesterase type 4 inhibitors
Roflumilast
- It helps in reducing exacerbations, improve dyspnea, and increase lung function in patients with severe COPD.
GOLD recommendations for management of COPD
Stage | Degree of airway obstruction | Treatment |
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Stage I | Mild |
|
Stage II | Moderate |
|
Stage III | Severe |
|
Stage IV |
Very severe or moderate with evidence of chronic respiratory failure |
|
Symptoms for admission to emergency department
- Confusion
- Lethargy
- Labored breathing (respiratory muscle fatigue)
- Blue discoloration of skin (indicating worsening hypoxemia)
- Worsening respiratory acidosis (pH < 7.30)
Trial supportive data
Use of long acting anticholinergics like Tiotropium have shown a reduction in frequency of COPD exacerbations, hospitalization and improvement in quality of life when compared with placebo. However, these drugs didn't show any improvement in FEV1 or mortality benefits. Additionally, two recently conducted large randomized trials compared tiotropium (anticholinergics) with salmeterol (long acting beta agonist)and placebo. Both the studies showed increased benefits in lung function tests, symptoms and quality of life with tiotropium when compared to salmeterol. Other studies showed tiotropium to decrease the number of exacerbation when compared with salmeterol.
External link
References
- ↑ Belman MJ, Botnick WC, Shin JW (1996). "Inhaled bronchodilators reduce dynamic hyperinflation during exercise in patients with chronic obstructive pulmonary disease". American Journal of Respiratory and Critical Care Medicine. 153 (3): 967–75. PMID 8630581. Retrieved 2012-03-20. Unknown parameter
|month=
ignored (help) - ↑ Maclay JD, Rabinovich RA, MacNee W (2009). "Update in chronic obstructive pulmonary disease 2008". American Journal of Respiratory and Critical Care Medicine. 179 (7): 533–41. doi:10.1164/rccm.200901-0134UP. PMID 19318543. Retrieved 2012-03-20. Unknown parameter
|month=
ignored (help) - ↑ Rice KL, Dewan N, Bloomfield HE, Grill J, Schult TM, Nelson DB, Kumari S, Thomas M, Geist LJ, Beaner C, Caldwell M, Niewoehner DE (2010). "Disease management program for chronic obstructive pulmonary disease: a randomized controlled trial". American Journal of Respiratory and Critical Care Medicine. 182 (7): 890–6. doi:10.1164/rccm.200910-1579OC. PMID 20075385. Retrieved 2012-03-20. Unknown parameter
|month=
ignored (help) - ↑ Dewan NA, Rice KL, Caldwell M, Hilleman DE (2011). "Economic evaluation of a disease management program for chronic obstructive pulmonary disease". Copd. 8 (3): 153–9. doi:10.3109/15412555.2011.560129. PMID 21513435. Retrieved 2012-03-20. Unknown parameter
|month=
ignored (help) - ↑ Chapman KR, Rennard SI, Dogra A, Owen R, Lassen C, Kramer B (2011). "Long-term safety and efficacy of indacaterol, a long-acting β₂-agonist, in subjects with COPD: a randomized, placebo-controlled study". Chest. 140 (1): 68–75. doi:10.1378/chest.10-1830. PMID 21349928. Retrieved 2012-03-19. Unknown parameter
|month=
ignored (help) - ↑ Singh S, Furberg CD (2011). "Inhaled anticholinergics for chronic obstructive pulmonary disease: comment on "Inhaled anticholinergic drug therapy and the risk of acute urinary retention in chronic obstructive pulmonary disease"". Archives of Internal Medicine. 171 (10): 920–2. doi:10.1001/archinternmed.2011.171. PMID 21606097. Retrieved 2012-03-21. Unknown parameter
|month=
ignored (help) - ↑ Vogelmeier C, Hederer B, Glaab T, Schmidt H, Rutten-van Mölken MP, Beeh KM, Rabe KF, Fabbri LM (2011). "Tiotropium versus salmeterol for the prevention of exacerbations of COPD". The New England Journal of Medicine. 364 (12): 1093–1103. doi:10.1056/NEJMoa1008378. PMID 21428765. Retrieved 2012-03-19. Unknown parameter
|month=
ignored (help)