respiratory drugs Flashcards
how can respiratory drugs be administered
- variety of ways
- inhalation
- oral
- intravenous
what type of administration is asthma
- topical
- inhaler powder doesn’t make it to the alveoli so not inhalation
- air flow slows and particles stick on airway wall instead
why is ventilation needed
- to make sure airways are opened more
- open more = more airflow
what is seen as the only function of the lungs
gas exchange
if ventilation doesn’t work what does that mean
- gas exchange won’t work either
- want to ventilate CO2 out and O2 in
what do muscles on chest wall do
- create a negative pressure in the lungs
- if you have narrowed airways then its difficult for gas to get in
what do bronchodilators do
- open airway up
- opens diameter of tube
what do anti-inflammatory do
- reduce swelling of lining, reducing oedema
what happens in most of respiratory disease
- inflammation of bronchi which is like atherosclerosis
- makes bronchi narrower so gas exchange is harder
what are bronchodilators
- beta2 agonists widens airways = beta 2 receptors are avoided in asthma as it makes ventilation harder
- anticholinergic = prevents muscle constriction to open airways
what are anti-inflammatories
- corticosteroids = switch off inflammatory process in mucosa so mucosa can shrink to airway is wider
what prevents mast cell degranulation
- chromoglycate
- leukotriene receptor antagonists
what drugs impart ventilation
- beta blockers
- respiratory depressants = benzodiazepines make you drowse so can’t breathe as well, opioids in a high dose can completely switch off respiratory drive
what drugs improve gas exchange
- only way to improve gas exchange is to improve ventilation
- respiratory stimulants = theophyllines
- oxygen = this is a drug, only a medicine if you give it in a higher concentration than in air, must be prescribed like any other drug (if have a disease of the alveoli it is more difficult for O2 to get through from blood to alveoli
what are the 2 ways of inhaled drug delivery
- meter dose inhaled (MDI)
- breath activated device