COPD Therapy Flashcards
Are bronchodilators effective in COPD?
They have limited efficacy
as bronchoconstriction is not the main form of lung obstruction in COPD
Which Muscarinic antagonists are most commonly prescribed in COPD?
Ipratropium and Tiotropium
How does Ipratropium work?
it is a NON-SELECTIVE muscarinic antagonist (works on both M2 and M3 receptors)
M3 is advantageous as it prevents smooth muscle contraction and prevents mucus secretions
M2 is a feedback receptor and so blocking this will increase the levels of synaptic ACh (not good)
How does Tiotropium work?
It is a selective M3 receptor antagonist
Preserves the M2 negative feedback pathway
What does blocking the M3 receptor do?
Prevents smooth muscle contraction
Prevents mucus secretion
Advantageous!
What does blocking the M2 receptor do?
Prevents the M2 feedback mechanism from occuring and so increases the levels of synaptic ACh
Not advantageous!
What controls mucus secretion?
- The Parasympathetic nervous system
- Neurokinins (released from sensory nerves stimulated by irritants)
What can neurokinin inhibitors be used to treat in COPD?
Mucous secretion
What could EGFR inhibitors be used to treat in COPD?
Mucous secretion
- (e.g. Erlotinib)
Are Phosphodiesterase inhibitors effective in COPD?
Yes
PDEIII - Airway smooth muscle
PDEIV - Leukocytes
(Roflumilast is a selective PDEIV inhibitor)
What type of antibiotics can be useful in COPD?
Macrolides
- May prevent alveolar destruction following smoke injury
How does N-acetyl cysteine work?
it is a Mucolytic
Is DNAase effective in COPD?
No. Only in cystic fibrosis
What is the main problem with glucocorticoids in COPD?
They do not address the inflammation in COPD (Limited success)
- They inihibit Neutrophil apotosis (upregulated in COPD so not good!)
- Smoking also activates NFkB and suppresses HDAC which work against the effect of glucocorticoids
