MUR Tips

Chronic Obstructive Pulmonary Disease (COPD)

Background

Chronic obstructive pulmonary disease (COPD) is the globally accepted term to describe the spectrum of respiratory conditions that includes chronic bronchitis, emphysema and long standing chronic asthma that has become less responsive to therapy. It is characterised by airflow obstruction which is usually progressive, not fully reversible and does not change markedly over several months.

COPD is NOT Asthma

The differentiation of COPD from asthma is complicated since these diseases share bronchial obstruction as a common symptom and may produce similar changes in lung function. However, the underlying disease processes are different and require different management and treatment. Far too often COPD patients are treated as asthmatics.

COPD / ASTHMA
Smoker or ex-smoker / Nearly all / Possibly
Symptoms under age 35 / Rare / Often
Chronic productive cough / Common / Uncommon
Breathlessness / Persistent and progressive / Variable
Night time waking with breathlessness and or wheeze / Uncommon / Common
Significant diurnal or day to day variability of symptoms / Uncommon / Common
There is no cure, so management is focused on relieving symptoms, preventing exacerbations / complications and improving patient’s quality of life. The overall approach to managing stable COPD should be characterised by a stepwise increase in treatment, depending on the severity of the disease. It should be based on an individualised assessment of disease severity, patient’s symptoms and response to treatments. Treatments should be monitored closely and adjusted accordingly.

Inhaled bronchodilators - both short-acting and long-acting are commonly used. Inhaled corticosteroids, mucolytics, and methylxanthines also have a role, as do oral steroids and antibiotics during acute exacerbations, and oxygen and nebulised therapy in patients with severe COPD.

Dosage regimen

Class / Examples / Frequency
Inhaled short-acting beta2 agonists / salbutamol, terbutaline / PRN (severe patients may use frequently throughout the day
Inhaled long-acting beta2 agonists / salmeterol, formeterol / twice a day
Inhaled short-acting anticholinergic / ipratropium / three or four times a day
Inhaled long-acting anticholinergic / tiotropium / once a day
Mucolytics / carbocisteine, erdosteine, mecysteine / divided doses throughout the day
Methylxanthines / slow release theophylline, aminophylline / every 12 hours
Inhaled corticosteroids / beclometasone, fluticasone, budesonide / twice a day
Inhaled combination inhalers (corticosteroid plus long- acting beta2 agonist) / seretide, symbicort / twice a day

Patient's knowledge of the medicine's use

  • Beta2 agonists relax airway smooth muscle and reduce breathlessness.
  • The onset of action of the short-acting beta2- agonists (SABA) is slower than in patients with asthma and COPD patients experience more adverse effects than asthmatics. The effects last for up to 4 hours and patients can use SABAs on a regular or as required basis.
  • Long-acting agents should be used by individuals who remain symptomatic or who have two or more exacerbations in a year.The advantages are that they produce a sustained relaxation of the airway of approximately 12 hours. The degree of bronchodilation is similar to a SABA.
  • Anticholinergics reduce breathlessness and mucus secretion.
  • Short-acting agent (ipratropium) may be used when required or regularly up to four times a day. The onset of action is slower than beta-2-agonists, approximately one hour, but the bronchodilation is more sustained (up to 8 hours) and at least as effective, and possibly more so. In practice many COPD patients benefit from anticholinergics.
  • Long-acting agent, tiotropium, may be used if the patient remains symptomatic or has had experienced two or more exacerbations in a year.
  • Ipratropium and Tiotropium should not be prescribed at the same time.
  • Theophylline and its derivatives have a small bronchodilator effect in COPD and may have anti-inflammatory activity although the later has yet to be fully assessed. Theophylline may also increase diaphragmatic strength in patients with COPD and have effects on mucociliary clearance. However due to the potential toxicity and significant interactions with other drugs theophylline is recommended for use when other treatments have failed or when a patient remains symptomatic despite optimal bronchodilator therapy.
  • Corticosteroids have an anti-inflammatory effect. Inhaled corticosteroids may be used in combination with a long-acting beta2 agonist for patients with moderate to severe COPD. A short course of oral steroids should be given if the increased breathlessness of an exacerbation interferes with daily activities.
  • Mucolytics clear excess sputum to make breathing easier. They may be employed to reduce exacerbations in COPD patients who have a chronic cough.The prescription should only be continued if there is symptomatic improvement after 4-6 weeks of therapy.

Is the medicine working?

Patients with COPD must be regularly assessed to determine whether they are benefiting from their treatment regimens. If there is no benefit, therapy must be modified. Asking the following questions will show how effective drug treatment is, and the impact the condition has on the patient's life:

Side effects

Beta2 agonists / The side effects are dose related, resulting from systemic absorption, and include tremor, cramp, nervousness and palpitations. To avoid these the dose of salbutamol should not exceed 1 mg. This is difficult to achieve when patients are prescribed nebulisers, as the lowest dose unit of salbutamol is 2.5 mg. The lowest dose possible should be prescribed.
Anticholinergics / Dry mouth, blurred vision and paradoxical bronchospasm.
If ipratropium is being nebulised, the mask must be fitted carefully or ideally a mouthpiece used to avoid the aerosol coming into contact with the eyes, which could cause glaucoma.
Methylxanthines / Nausea, headaches and gastro-intestinal reflux, headache and palpitations.
Corticosteroids / Inhaled corticosteroids:
Hoarseness or candidiasis, advise to rinse the mouth with water after use or to use a spacer.
There is a potential risk of patients developing osteoporosis and other side effects from treatment with high dosages of inhaled corticosteroids.
Oral corticosteroids: can produce a long list of side effects. These should be restricted to only patients who require them for an exacerbation of their COPD
Mucolytics / Rarely cause rashes and gastrointestinal bleeds

Lifestyle

* Encourage the patient to lose or increase weight (depending on the situation).

* Encourage smokers to stop smoking as this is an important factor in the progression of the disease. Monitor patients on methylxanthines as smoking can cause considerable variations in plasma-theophylline concentrations.

* Pulmonary rehabilitation can be used to improve social and physical performance.

Resources for Patients

Breath Easy Group of the British Lung Foundation, 73-75 Goswell Road, London EC1V 7ER, or telephone Helpline on 08458 50 50 20 or see website:

Anna Murphy, June 2008