Asthma Drugs

Question 1

List all of the common Asthma drugs

Answer 1

Inhaled corticosteroids (ICS)
Beta 2 agonists
Leukotriene receptor antagonist
Long-acting muscarinic antagonist
Theophylline

Question 2

List the step-wise treatment pathway for Asthma

Answer 2

1. Regular preventer - low dose ICS
2. Add on therapy - inhaled LABA
3. Additional controller therapies - increase ICS to medium dose ICS, or add leukotriene receptor antagonist
4. Specialist care

Question 3

List the following for: Inhaled corticosteroids (ICS)

• Use
• Example drugs
• Drug class
• Mechanism of action
• Adverse effects
• Warnings / contraindications

Answer 3

Asthma preventer (when reliever not sufficient)
Reduces symptoms, exacerbations and prevents death

Beclomethasone
Budesonide
Fluticasone

Inhaled corticosteroids (ICS)

Anti-inflammatory properties

• Activates cytoplasmic receptors (goes into nucleus to modify transcription)
• Reduce mucosal inflammation, widens airway and reduces mucous

Local immunosuppressive action

• Candidiasis
• Hoarse voice
• Pneumonia – possible in COPD in higher doses

Question 4

List the following for: Beta 2 agonists

• Use
• Example drugs
• Drug class
• Mechanism of action
• Adverse effects
• Warnings / contraindications
• Important drug reactions

Answer 4

SABA – Symptom relief as required
LABA – Add on therapy to SABA and ICS

SABA:
Salbutamol
Terbutaline
LABA:
Salmeterol 
Formoterol

Beta2 agonists

• Major action at bronchial smooth muscle – prevent bronchoconstriction before exercise
• Increase mucous clearance by action of cilia

Adrenergic effects:

• Tachycardia
• Palpitations
• Anxiety and tremor
• Increased glycogenolysis
• Increased renin production
• LABA only prescribed alongside ICS
• CVD
• Beta blockers (caution)

Question 5

List the following for: Leukotriene receptor antagonist

• Use
• Example drugs
• Drug class
• Mechanism of action
• Adverse effects

Answer 5

Alternative to LABA (as add on therapy)

Montelukast

Leukotriene receptor antagonist

• Block CysLT1 at CYSLTR1 – prevents binding of leukotrienes (released by mast cells)
• Prevents some bronchoconstriction
• Reduces mucous
• Reduces oedema
• Headache
• GI disturbance
• Dry mouth
• Hyperactivity

Question 6

List the following for: Long-acting muscarinic antagonist

• Use
• Example drugs
• Drug class
• Mechanism of action
• Adverse effects

Answer 6

Severe asthma and COPD

Tiotropium

Long-acting muscarinic antagonist

• Block vagal mediated contraction of airway smooth muscle

Infrequent – anticholinergic effects

• Dry mouth
• Urinary retention
• Dry eyes

Question 7

List the following for: Theophylline

• Use
• Drug class
• Mechanism of action
• Warnings / contraindications
• Important drug reactions

Answer 7

For chronically poorly controlled asthma

Adenosine receptor antagonist

• Adenosine receptor antagonist
• Reduce bronchoconstriction
• Very narrow therapeutic index – plasma concentration monitoring required
• CYP450 inhibitors