asthma drugs

Question 1

what are the first line therapy drug treatments for asthma?

Answer 1

glucocorticoids (steroids) and bronchodilators (e.g. b2 adrenergic agonists)

Question 2

what is chronic asthma;

Answer 2

recurrent attacks of reversible airway obstruction of air flow

Question 3

function of the airways?

Answer 3

to carry oxygen and carbon dioxide between the alveoli in the lungs and the air (mouth)

Question 4

what happens to the airways during asthma?

Answer 4

they become constricted due to inflammation, muscle contraction or excessive mucus secretion

Question 5

features of asthma?

Answer 5

characterised by inflammation of the airways and hyper-reactivity of the bronchioles, resulting in bronchoconstriction and mucus secretion.

Question 6

aim of asthma drug treatments?

Answer 6

to reduce inflammation, prevent bronchoconstriction and restore airways calibre to normal

Question 7

stimuli that may trigger an asthma attack?

Answer 7

exercise and cold air, respiratory infection, atmospheric pollutants, allergens in sensitised people; pollen, dust mite proteins and animal dander

Question 8

how does asthma develop?

Answer 8

when allergen is presented, B cells are activated via the T cell cascade to produce IgE’s which recognise the antigen. high affinity binding of IgE’s and mast cells occurs resulting in inflammatory cell recruitment and bronchoconstriction

Question 9

describe the immediate/early phase of asthma attack?

Answer 9

bronchospasm: bronchial muscle contracts causing mast cells to release spasmogens. mast cells then release inflammatory mediators such as interleukins

Question 10

describe the late phase of asthma attack?

Answer 10

progressing inflammatory reaction; Th2 lymphocytes and eosinophils invade and there is a release of cytokines, chemokines and toxic proteins

Question 11

what can agents of inflammatory mediators cause?

Answer 11

damage to and loss of bronchial epithelium, smooth muscle cell hypertrophy and hyperplasia and hyper-reactivity to irritant stimuli

Question 12

examples of bronchodilator drugs?

Answer 12

B2 adrenergic receptor agonists, theophylline, muscarinic receptor antagonists, leukotriene receptor antagonists

Question 13

function of bronchodilators?

Answer 13

dilate bronchioles and increase air flow to the alveoli, relax smooth muscle cells around walls of bronchioles

Question 14

action of B2 adrenergic receptor agonists?

Answer 14

act on B2 adrenoceptors on bronchiole smooth muscle to relax muscle; inhibit mediator release from mast cells and monocytes; act on cilia to increase mucus clearance

Question 15

describe SHORT acting B2 adrenergic receptor agonists?

Answer 15

salbutamol, terbutaline - max effect occurs in 30 mins, lasts 4-6 hours. used as needed to control asthma symptoms

Question 16

describe long acting B2 adrenergic receptor agonists?

Answer 16

salmeterol - duration of action is 12 hours, used 2x daily

Question 17

side effects of B2 adrenergic receptor agonists?

Answer 17

tremor, some tolerance may develop

Question 18

why is theophylline administered?

Answer 18

used with steroids when asthma response to B2 agonists is inadequate. e.g. xanthine

Question 19

unwanted effects of theophylline?

Answer 19

stimulates the CNS causing tremor and sleep disturbance, stimulates the heart and causes vasodilation, GI effects such as anorexia, nausea and vomiting

Question 20

actions of muscarinic receptor antagonists?

Answer 20

relax bronchial smooth muscle, inhibit elevated mucus secretion, increase clearance of bronchial secretions, block action of endogenous acetylcholine at muscarinic receptors

Question 21

example of a muscarinic receptor antagonist?

Answer 21

ipratropium

Question 22

examples of leukotriene receptor antagonists?

Answer 22

montelukast (1x day) zafirlukast (2x day)

Question 23

unwanted effects of leukotriene receptor antagonists?

Answer 23

headache, GI disturbance

Question 24

action of leukotriene receptor antagonists?

Answer 24

used as an add-on with B2 agonists, work against exercise-induced and aspirin sensitive asthma

Question 25

examples of glucocorticoids (anti-inflammatory drugs):

Answer 25

beclomethasone, diproprionate, budesonide, fluticasone, propionate, prednisolone, hydrocortisone

Question 26

action of glucocorticoids?

Answer 26

reduce production of cytokines, spasmogens, and leucocyte chemotaxins to reduce bronchospasm and the recruitment and activation of inflammatory cells

Question 27

unwanted effects of glucocorticoids?

Answer 27

inhaled steroids; oropharyngeal thrush, dysphonia. oral; adrenal suppression - patients must carry steroid card

Question 28

action of cromoglicate?

Answer 28

reduce early and late phase responses in asthma, reduces bronchial hyper-sensitivity, stabilises mast cells

Question 29

unwanted effects of cromoglicate ?

Answer 29

irritation of upper respiratory tract, hypersensitivity reactions

Question 30

what is omalizumab?

Answer 30

a biologic agent, a recombinant DNA-derived humanized IgG1 monoclonal antibody

Question 31

action of omalizumab?

Answer 31

binds to human IgE and inhibits binding of IgE to IgE receptor on mast cells, inhibiting IgE-mediated cascade of asthma

Question 32

unwanted effects of omalizumab?

Answer 32

anaphylaxis, malignancies

Question 33

which asthma treatment should be used for mild asthma with rare attacks?

Answer 33

inhaled B2 agonist when required

Question 34

which asthma treatment should be used for mild asthma with frequent attacks?

Answer 34

glucocorticoid for prophylaxis, B2 agonist when needed for acute attacks

Question 35

which asthma treatment should be used for moderate to severe asthma?

Answer 35

drug combination; B2 agonist with glucocorticoid in combined inhaler