how do muscarinic antagonists work?
SAMA/ LAMA mechanism: competitive inhibition of muscarinic receptors on bronchiole smooth muscle. By antagonising Ach action, this prevents increase for intracellular calcium which causes bronchodilation.
why are SAMA/ LAMA used more in COPD than asthma?
how long does LAMA effect last?
24hrs
what are the side effects of LAMA?
why are LAMA and LABA used together?
further benefits – better lung function, improved symptoms, better exercise tolerance.
what therapy is not recommended as monotherpay within COPD?
ICS - modest effect in relieving breathlessness/ lung function
what are the side effects of corticosteroids?
glaucoma, central fat deposition, osteoporosis, increased risk of infection, hirsutism, peptic ulcer, increased appetite, emotional disturbances, hypotension, hypokalaemia
what is the action of theophylline/ aminophylline?
vasodilator, anti-inflammatory, contributes to immunomodulatory actions
what is aminophylline hydrolysed to?
rapidly hydrolysed after absorption from gut to theophylline
what are the side effects of theophylline/ aminophylline?
what does theophylline/ aminophylline react with?
many antibiotics
before nebulising a breathlessness patient who isnt responding to therapy what should you check?
inhaler technique
when are mucolytic used?
used in patients with chronic productive cough with thick vicious sputum
what is contra indicated with mucolytic medication?
history of peptic ulcer
define acute exacerbating COPD?
sustained or worsening symptoms from usual stable state, which is beyond day to day variations with acute onset
what are the non defining symptoms of acute exacerbating asthma?
what is the management of exacerbated COPD?
which COPD can take prophylatic AB?
those who do not smoke
what primarily causes COPD?
smoking
describe COPD
COPD: predominately caused by smoking and characterised by airflow obstruction that is not fully reversible, does not change markedly over several months and is usually progressive
- Exacerbations often occur where there is rapid and sustained worsening of symptoms beyond normal day to day variations and require change in treatment.
what are the symptoms of COPD?
wheezing, lip pursing, chronic productive cough, barrel chest, dyspnoea, prolonged expiratory time, bronchitis – increased sputum, digital clubbing
what are the clinical features of COPD?
Clinical features: easily fatigued, frequent resp infections, use of accessory muscles for normal breathing, orthopneic, cor pulmonale (later in disease), thin appearance
what is emphysema?
alveolar destruction - alot bigger hence less SA
how quick can hypoxia occur?
seconds/ minutes