Respiratory Pharmacology

Question 1

Describe Step 1 in the treatment of asthma and name some side effects of the drugs used

Answer 1

Step 1 is for mild-intermittent asthma

GIve short acting beta-2 agonist

Provides symptom relief through reversal of bronchoconstriction

Side effects of beta-agonist use includes tachycardia, palpitations and tremour

Question 2

Name some short acting beta-2 agonists

Answer 2

Salbutamol

Terbutaline

Question 3

What happens if beta-2 agonists are used regularly

Answer 3

If used regularly, beta-2 agonists reduce asthma control as regular use causes increased mast cell degranulation in response to allergens causing increased inflammation

Beta-2 agonist used may inhibit mast cell degranulation if used intermittently

Question 4

Name some inhaled corticosteroids

Answer 4

Beclomethasone dipropionate

Budesonide

Fluticasone

Question 5

Describe Step 2 in the treament of asthma and how does it help treat asthma

Answer 5

Step 2 is regular preventer therapy using inhaled corticosteriods

Inhaled corticosteriods help improve symptoms and lung function, reduce exacerbation and prevent death

Corticosteroids inhibit eosinophils so help prevent eosinophilic inflammation occuring (eosinophils are a major cause of inflammation in asthma)

Question 6

Describe Step 3 in the treatment of asthma and why the drugs may be combined into a single inhaler

Answer 6

Add on a long acting beta-2 agonist.

Add in LABA when patient not controlled while using inhaled corticosteroids. LABA not anti-inflammatory

LABA and ICS may be combined for ease of use, increased compliance, less prescriptions to worry about and for safety

Question 7

Name some long acting beta-2 agonists

Answer 7

Salmeterol

Formoterol

Question 8

What should be checked before initiating new drug therapy in Step 3 of asthma treatment

Answer 8

Check compliancy

Check inhaler technique

Eliminate trigger factors

Question 9

What other add ons can be given in Step3/4 of asthma treatment

Answer 9

High dose ICS

Leukotriene receptor antagonists

Methyxanthines

Long acting anticholinergics (LAMAs)

Question 10

Describe how leukotriene receptor antagonists work and some side effects seen with their use

Answer 10

Leukotriene receptor antagonists inhibits LTC4 action (produced by mast cells and eosinophils) by blocking its receptor

Side effects include: angioedema, dry mouth, anaphylaxis, arthralgia, fever, gastric disturbances, nightmares

Question 11

Name some leukotriene receptor antagonists

Answer 11

Montelukast

Zafirlukast

Question 12

Describe how methylxanthines work and some side effects seen with their use. What DDIs do they have

Answer 12

Methylxanthines antagonise adenosine receptors and inhibit phosphodiesterase to increase cAMP in cells

Side effects include: headache, nausea, reflux, arrhythmias, fits

Methylxanthine levels are increased by CYP450 inhibitors, e.g. erythromycin, ciprofloxacin

Question 13

Name some methylxanthines

Answer 13

Theophylline

Aminophylline

Question 14

Describe how long acting anticholinergics help in asthma and COPD and the side effects seen with their use

Answer 14

LAMAs help reduce exacerbations in COPD and asthma. They have a small improvement on lung function and symptoms

Are selective for M3 muscarinic receptors

Side effects: dry mouth, urinary retention, glaucoma

Question 15

Name some LAMAs and whether they are used for COPD and/or asthma

Answer 15

Tiotropium bromide (SPIRIVA) - asthma and COPD

Iprotrapium bromide - asthma and COPD

Aclidinium - COPD

Umeclidinium - COPD

Glycopyrronium - COPD

Question 16

What types of drugs are used during Step 5 of asthma treatment and name some drugs in each catagory

Answer 16

Anti-IgE - e.g. omalizumab

Anti-IL-5 - e.g. mepolizumab, reslizumab

Question 17

Describe how Anti-IgE drugs work

Answer 17

Anti-IgE potentially reduce exacerbation rates in patients not controlled on oral steroids

They prevent IgE binding to high affinity IgE receptors but cannot bind to IgE already bound to receptor so prevent cross linking of IgE so mast cells are not activated

Question 18

Describe how Anti-IL-5 drugs work

Answer 18

Anti-IL-5 reduce eosinophil numbers in peripheral blood and in airways

Reduce rates of severe asthma exacerbations and allow for steroid tapering

Question 19

What is the treatment of acute, severe asthma

Answer 19

Oxygen

Nebulised salbutamol

PO prednisolone daily for 10-14 days

Nebulised iprotrapium bromide if moderate exacerbation not responding or if acute severe/life threatening

IV aminophylline if no improvement and life threating features not responding to treatment