Pharmacology Of Airway Control

Question 1

Name the 5 stages of asthma management.

Answer 1

1 - mild intermittent asthma
2 - regular preventer therapy
3 - add on therapy
4 - persistent poor control
5 - frequent oral steroid use

Question 2

What is ‘asthma control’?

Answer 2

Minimal symptoms, minimal need for reliever medication and no exacerbations.

Question 3

What is acute severe asthma?

Answer 3

Any of:

• unable to complete sentences
• pulse >110bpm
• RR > 25/min
• peak flow 33-50% of normal

Question 4

What is life-threatening asthma?

Answer 4

Acute sever asthma plus any of the following:

• peak flow <33% of normal
• spO2 < 92%
• pO2 <8kpa
• pCO2 > 4.5kpa
• silent chest
• cyanosis
• hypotension or bradycardia
• exhaustion, confusion, coma

Question 5

What is near fatal asthma?

Answer 5

When pCO2 >6kPa

Question 6

Name 2 B2 agonists used for asthma that are short acting and have a fast onset.

Answer 6

Salbutamol

Terbutaline

Question 7

Name a B2 agonist used for asthma that is long acting and has a fast onset.

Answer 7

Formoterol

Question 8

Name a B2 agonist used for asthma that is long acting and has a slow onset?

Answer 8

Salmeterol

Question 9

What should you do before initiating a new asthma treatment?

Answer 9

• check compliance with existing therapies
• check inhaler technique
• eliminate trigger factors

Question 10

What are the 2 routes that inhaled drugs can take to reach the systemic circulation?

Answer 10

• inhaled into lungs, absorbed into systemic circulation
• swallowed and absorbed from the gut into the bloodstream, passes through the liver therefore can undergo extensive first pass metabolism

Question 11

How is mild intermittent asthma managed?

Answer 11

Short acting B2 agonist used for symptom relief on an as-required basis.

Question 12

Why should a B2 agonist only be used as-required in mild intermittent asthma?

Answer 12

If used too regularly, they can reduce asthma control and this leads to an increase in mast cell degranulation.

Question 13

Name some side effects of B2 agonists.

Answer 13

Adrenergic side effects e.g. Tachycardia, palpitations, tremor.

Question 14

Which drugs are given for regular preventer therapy of asthma?

Answer 14

Inhaled corticosteroid started when patient is getting symptoms or using B2 agonist >3 times a week.

Question 15

What are beclomethasone dipropionate, budesonide and fluticasone used for and what is their MOA?

Answer 15

Inhaled corticosteroids used for regular preventer therapy of asthma.
Reduce mucous secretion, relieve bronchoconstriction and reduce eosinophil numbers.

Question 16

Which drugs are used in add on therapy of asthma control?

Answer 16

When patients are not controlled on inhaled corticosteroids, a long acting B2 agonist is given instead of a short acting one.

Question 17

Name 2 long acting B2 agonists.

Answer 17

Formoterol
Salmeterol
Both last for around 12 hours

Question 18

Why is it good to combine a long-acting B2 agonist and inhaled corticosteroids in one single inhaler?

Answer 18

Increases compliance and safety - if they were separate, patients are more likely to only take the fast acting reliever and not take the longer acting B2 agonist.

Question 19

Of formoterol and salmeterol, which is more potent?

Answer 19

Formoterol (has a lower EC50)

Question 20

Which drugs are given in persistent poor control of asthma?

Answer 20

If previous therapies haven’t worked, can:

• increase dose of inhaled corticosteroids
• give leukotriene receptor antagonists
• give methylxanthines
• give long-acting anticholinergic

Question 21

Name 2 leukotriene receptor antagonists used for asthma, and what is their MOA?

Answer 21

Montelukast
Zafirlukast
Inhibit leukotrienes to prevent bronchoconstriction.

Question 22

Name 2 anti-muscarinics used for asthma control. What is their MOA?

Answer 22

Ipratropium bromide
Tiotropium bromide
M3 antagonists

Question 23

What drug class are aminophylline and theophylline and what are they used for?

Answer 23

Methylxanthines, used for persistent poor asthma control.

MOA: adenosine antagonists

Question 24

Name 3 inhaled corticosteroids used for asthma control.

Answer 24

Beclomethasone dipropionate
Budenoside
Fluticasone

Question 25

Which oral steroid is most commonly sued for asthma?

Answer 25

Prednisolone

Question 26

What is the optimum particle size for inhaled steroids?

Answer 26

1-5 microns is optimum for getting into the small airways. If too big they get deposited in the mouth and oropharynx, if too small they are inhaled and exhaled from alveoli without being deposited.

Question 27

How is acute severe asthma treated?

Answer 27

1. Give high flow O2 to titrate sats to 94-98%
2. Give nebulised salbutamol
3. Give oral prednisolone
4. If it becomes life-threading, add nebulised ipatropium bromide and IV aminophylline