RESPIRATORY DRUGS Flashcards
At what concentration is oxygen normally administered and why?
60%
if higher can increase risk of hypoventilation and CO2 retention
when is high concentration oxygen administered?
critically ill patients
give an example of a beta 2 agonist
Short acting: salbutamol, terbutaline
Long acting: salmeterol, formoterol,
give a instances when administration of oxygen should be done with caution/not at all
Type 2 respiratory failure (severe COPD) due to the compensation mechanism
how do beta 2 agonists work?
stimulate smooth muscle receptors in lungs and activate cAMP which relaxes smooth muscle - reduces airway resistance
Give instances when short and long acting beta 2 agonists are used?
Asthma: short acting are used for relieve of breathlessness but long is used as step 3 treatment for chronic asthma
COPD: short is used for relieving breathlessness and long is used in step 2 of treatment
Hperkalaemia: nebulised salbutamol used in addition with insulin, glucose and calcium gluconate
give 4 administration methods for beta 2 agonists
oral
inhaled
IV
nebulised
give 3 contraindications for use of beta 2 agonists
Hypersensitivity
pre-existing cardiac tachy-arrythmia
pregnancy (cleft palette)
give a cardiac side effect of beta 2 agonists
palpitations/tachycardia
give an electrolyte side effect of salbutamol
hypokalaemia
give 4 other side effects of beta 2 agonists
fine tremor
nervousness
anxiety
Muscle cramps ( caused by long acting)
how do beta 2 agonists interact with beta blockers?
Reduce the effect of beta 2 agonists
why should high doses of beta 2 agonists be used cautiously with either diuretics, theophylline or corticosteroids?
can potentiate hypokalemia
why should infused beta 2 agonists not be used with methyldopa?
Can cause acute hypotension
give an example of an anticholinergic (antimuscarinic)
long acting= tiotropium
Short acting= ipratropium
how do antimuscarinic work?
It is competitive inhibitor of acetylcholine on the muscarinic receptor. Which blocks the parasympathetic effects (rest and digest) therefore:
Increase heart rate and conduction
Reduce smooth muscle tone in the respiratory tract
Reduced secretion of glands in the respiratory glands and GI tract
Inthe eye they cause relaxation of the pupillary constrictor and ciliary muscles, causing pupillary dilatation and preventing accommodation,
respectively
when are antimuscarinic used?
COPD: short acting is used to relieve breathlessness caused by exercise and long acting is used for prophylaxis of exacerbation and breathlessness
Asthma: short acting is used with conjunction with short beta 2 agonist for acute exacerbation while long acting is used in step 4 treatment of chronic asthma with inhaled corticosteroids and long acting beta 2 agonist
how are anticholinergics taken?
capsules inside inhalation device
why are anticholinergics contraindicated in narrow angle glaucoma?
can worsen symptoms causing pain, blurred vision and corneal oedema by increase intraocular pressure
give a renal side effect of anticholinergics
urinary retention
how are anticholinergics metabolised?
barely metabolised, 75% in urine
give an example of a corticosteroid
prednisolone, hydrocortisone and dexamethasone
what are the effect of corticosteroids?
1) Promote of anti inflammatory genes and inhibitor of pro inflammatory genes
2) Metabolic effect causing glucogensis
3) Mineralocorticoid effects of water and sodium retention and potassium excretion via urine
Give 4 examples of when corticosteroids are used
1) Treatment of inflammatory disorders and allergic reaction: anaphylaxis and asthma/COPD
2) suppression of autoimmune disease= IBD or inflammatory arthritis
3) Used in chemotherapy or reduce tumour induced inflammation
4) Hormonal replacement in adrenal insufficiency and hypopituitarism
why are corticosteroids contraindicated in chickenpox and shingles?
can make diseases more severe
give a contraindication of corticosteroids
systemic fungal infection and immunosuppression
Give a GI side effect of corticosteroids
peptic ulcer
What is the side effect caused by the mineralocorticoid effects of corticosteroids?
hypertension
Oedema
Hypokalaemia
give an electrolyte side effects of corticosteroids
hypernatraemia and hypokalaemia
Give a hormonal/endocrine side effects of corticosteroids
cushingoid state
growth suppression in children
Adrenal suppression
GIve an oral side effect of corticosteroids
oral thrush
give a facial side effect of corticosteroids
facial oedema + petichiae
how are corticosteroids metabolised?
broken down by and induce cytochrome p450
give an example of a mucolytic
carbocysteine and erdosteine
how does carbocysteine work?
dissolve mucus and lower viscosity - helps with clearance
when are mucolytics used?
COPD
bronchiectasis
paracetamol overdose
give 2 contraindications for use of mucolytics
active peptic ulceration
pregnancy in the first trimester
give 2 respiratory side effects for mucolytics
bronchoconstriction
respiratory tract irritation
give a systemic side effect for mucolytics
pyrexia
give an ENT side effect for mucolytics
rhinorrhoea
why shouldn’t mucolytics be used with antitussives?
cough suppressants + increased mucus production is a bad combo
in what 4 ways does theophylline work?
phosphodiesterase inhibitor - reduces inflammation and innate immunity
Adenosine receptor antagonist = reduce inflammation
reverse steroid insensitivity
reverse effects of oxidative stress
give 2 indications for theophylline
COPD
asthma
give 4 contraindications for theophylline
active peptic ulcer disease
underlying seizure disorders
Hepatic impairment
Pregnancy –> neonatal irritability and apnoea has been reported
give a cardiac side effect for theophyllines
arrhythmias/tachycardia
give 2 other side effects of theophyllines
Nausea and vomiting
headache
dizziness
insomnia
how is theophylline metabolised?
cytochrome p450
When is oxygen administrated?
To increase oxygen tissue delivery for any condition that causes hypoxemia
To increase reabsorption of pleural gas in pneumothorax
To reduce the half life of carboxyhemoglobin in Carbon monoxide poisoning
When is it contradictory to give high flow oxygen?
When the patient has chronic type 2 respiratory failure as the patient has adapted to the hypoxia and hypercapenia
What should the aim of oxygen levels be for a patient who has type 2 respiratory failure
88%-92%
By giving high flow oxygen to a person with chronic type 2 respiratory failure what is the result?
Disruption to the adaptive state leading to rise in blood co2 levels.
Causing respiratory acidosis, impaired consciousness and worsened tissue hypoxia
What should long acting beta 2 agonist be administrated with when used for chronic asthma?
Be administrated with inhaled corticosteroids
What are the most common side effect of anticholinergics?
Dry mouth and throat irritation
What are the metabolic side effects of corticosteroids?
DM
Osteoporosis
Bone fracture
Interaction with what drugs increase risk of peptic ulcers with corticosteroids?
NSAIDS and aspirin. Consider giving gastroprotection
Interaction of corticosteroids with what drugs can cause hypokalaemia?
Beta 2 agonist, thiazides and loop diuretics and theophylline
What affect does corticosteroids have on vaccines?
Reduce the effect on the immune system
What drugs reduce the plasma levels of corticosteroids?
Drug that inhibit cytochrome p450 such as phenytoin and rifampicin
What affect does corticosteroid treatment have on adrenal cortisol production?
It causes the supression of pituitary ACTH secretion switching of stimulus for normal adrenal cortisol production
What is the effect of prolong corticosteroid treatment on the adrenal glands?
It causes adrenal atropy and prevents endogenous cortisol production
What is the risk of sudden withdrawel of long term corticosteroid use?
Patient develops acute addisons crisis with potential cardiovascular collapse
What is the treatment for step 1: mild, intermittent asthma?
Short acting Beta 2 agonist = salbutamol
What is the step 2 treatment for asthma?
Corticosteroids inhaled such as beclometasone budesonide and fluticasone
What is the step 3 treatment for asthma?
Inhaled long-acting beta2 agonists such as salmeterol and formoterol
Has to be given with inhaled corticosteroids
What improvements does step 3 have to asthma by the indication of long acting beta 2 agonist?
Improves lung function and symptoms and decreases asthma attacks in adults and children.
What is step 4 treatment for asthma?
Poor control when you are on inhaled steroids and additional treatment
Long acting muscranics: tiotropium
What is step 5 treatment for asthma?
Additional oral steroids such as prednisolone
Give examples of 3 inhaled corticosteroids?
beclometasone, budesonide, fluticasone
What is the use of inhaled corticosteroids for asthma?
Step 2 to treat airway inflammation and control symptoms
When is inhaled corticosteroids used for COPD?
Used to to control symptoms and prevent exacerbations in patients who have severe
airflow obstruction
With what drugs is inhaled corticosteroids used in conjuction with for COPD?
long-acting
β2-agonist and/or a long-acting antimuscarinic bronchodilator.
What is the function of the inhaled corticosteroids?
Reduces mucosal inflammation, widens the airways,and reduces mucus secretion.
This improves symptoms and reduces exacerbations in asthma and COPD
What are two common side effects of inhaled corticosteroids?
Oral candidasis (oral thrush) Hoarse voice
What side effect can inhaled corticosteroids induce in patients with copd?
pneumonia
What is the contradictions for high dose inhaled corticosteroids particularly fluticasone?
For COPD patients as can cause pneumonia
Children= cause growth suppresison
how many puffs can a patient take of salbutamol at any one time?
Up to 10 puffs with a minute between each
