Lecture 7: The pharmacology of COPD Flashcards
Is COPD reversible with bronchodilator treatment?
No
What mediates COPD?
Neutrophil and macrophages
What mediates COPD?
Neutrophil and macrophages
Compare asthma patients and COPD patients
- Inflamed airways narrowed by asthma
- Collapsed airways and damaged alveoli with COPD
- Exposure to triggers cause asthma attacks, periodically inflaming the lungs
- Long term exposure to damaging substances cause chronic inflammation of the lungs
What is the main goal of managing COPD?
Improving health status, reducing symptoms, preserving lung function decline, preventing exacerbations, and reducing mortality
What are the characteristics of stage 0 (at risk) COPD?
- Chronic symptoms (cough, sputum)
- Exposure to risk factors
- Normal spirometry
What is the recommended treatment for mild COPD?
Short-acting bronchodilator when needed
What are the characteristics of mild COPD?
- FEV1/FVC < 70%
- FEV1 < 80% predicted
- With or without symptoms
What is the recommended therapy for moderate COPD?
- Regular treatment with one or more bronchodilators
- Rehabilitation
- Inhaled Glucocorticosteroids if significant symptoms and lung function response
What are the charactersitics of moderate COPD?
FEV1 40 - 59%
What are the recommdended treatments for severe COPD?
- Regular treatment with one or more bronchodilators
- Inhaled glucorticosteroids if significant symptoms and lung function response or if repeated exacerbations.
- Treatment of complications
- Rehabilitation
- Long-term oxygen therapy if respiratory failure.
- Consider surgical treatments.
What are the characeristics of severe COPD?
FEV1 < 40%
What is the hallmark symptom of COPD?
Dyspnoea
Why do patients expiernece dyspnoea?
Dynamic hyperinflation as a result of increased lung volume
What does improvement in inspiratory capacity lead to?
reduced dyspnoea and improved exercise tolerance
How do beta 2 agonists act?
By binding to the β2AR
What are short acting beta 2 adrenoreceptor agonists?
- Salbutamol
- Piralbuterol
- Levalbuterol
What are long acting beta 2 adrenoreceptor agonists?
- Salmeterol
- Formeterol
- Arformeterol
Where are B2AR present?
- vascular endothelium
- ciliated cells
- circulating inflammatory cells (such as eosinophils)
- sub-mucosal glands.
What are the non bronchodilator effects of Beta 2 adrenoreceptor agonists?
- attenuation of mast cell mediator release
- reduction of plasma exudation
- reduced activation of sensory nerves
- enhancement of mucociliary transport
- attenuation of neutrophil recruitment
- inhibition of smooth muscle cell proliferation.
What is salbutamol used for in COPD?
Both in acute and chronic management of COPD
What is the onset of action of salbutamol?
3 minutes
When does salbutamol activity in COPD patinets peak?
After 2.5 hours
What is the duration of action of salbutamol?
4-6 hours
What was the result of SABA after seven days?
- improved post bronchodilator lung function in patients with moderate to severe COPD.
- Patients were also less dyspnoeic and more likely to comply with treatment.
What is an option for patients that are symptomatic despite regular SABA use?
Salmeterol and formoterol
Are Salmeterol and formoterol lipophilic or hydrophilic?
Lipophilic
Why is salmeterols onset of action slightly longer than formoterol?
Due to lipophilic properties that allow them to remain in the airway tissues in close vicinity to β2AR
What does the relative water solubility of formoterol allow it to do?
Enables it to diffuse rapidly to the β2AR and cause bronchodilation in between 1 to 3 minutes