Asthma

Question 1

What is the pathway for treatment of chronic asthma?

Answer 1

1. Occasional B2A for symptoms
2. Add standard dose inhaled steroid - Beclometasone
3. Add LABA (increasing steroid)
4. Consider trials of Beclo, theophylline, leukotriene receptor antagonist and modified release B2A tablets
5. Add regular pred

Note that rescue courses of pred can be prescribed at any time

Question 2

How do B2As work?

Answer 2

Relax bronchial smooth muscle (increase cAMP)
Acts within minutes

Salbutamol is best given as inhalation but can be given PO or IV

Question 3

What are side effects of SABAs?

Answer 3

Hypokalaemia
Tremor
Anxiety

Question 4

What are long acting B2A?

Answer 4

Salmeterol
Formoterol

Can help nocturnal sx and reduce morning dips

Can be alternative to increasing steroid dose when uncontrolled sx

Question 5

What are side effects fo LABAs?

Answer 5

Paradoxical bronchospasm
Hypokalaemia
Anxiety
Tremor

Question 6

How are steroids best taken?

Answer 6

Best inhaled to minimise side effects
Can be PO or IV

Rinse mouth after inhaled steroids to prevent oral candidiasis

Question 7

How to corticosteroids work?

Answer 7

Act over days to decrease mucosal inflammation

Question 8

When are steroids taken orally?

Answer 8

In acute setting - high dose and short courses

In longer term in lower doses if control not optimal on inhalers

Question 9

What are side effects of corticosteroids?

Answer 9

GI

• Pancreatitis
• Candidiasis
• Oesophageal ulceration
• Peptic ulceration

MSK

• Myopathy
• Osteoporosis
• Growth suppression
• Fractures

Endocrine

• Adrenal suppression
• Cushing’s syndrome

CNS

• Aggravated epilepsy
• Depression; psychosis

Eye

• Cataracts; glaucoma
• Papilloedema

Immune
Increased susceptibility to and severity of infections -> chickenpox
fever and increased WCC

Rarely cause leucopenia

Question 10

How does Aminophylline work?

Answer 10

Metabolised to Theophylline

Inhibits phosphodiesterase
Decreases broncho-constriction by increasing cAMP levels

Question 11

When should Aminophylline be tried?

Answer 11

Try as prophylaxis, at night, PO, to prevent morning dipping

Useful as adjunct if inhaled therapy is inadequate

May be given IVI in acute severe asthma

Question 12

What are dangerous aspects of aminophylline?

Answer 12

Narrow therapeutic range

Toxic range:
Arrhythmias
GI upset
Fits

Check levels and ECG monitoring
Check plasma levels after 24h if given IV

Question 13

What are examples of anticholinergics?

Answer 13

Ipratropium

Tiotropium

Question 14

What to anticholinergics do?

Answer 14

May reduce muscle spasm synergistically with B2A
Not recommended under current guidelines for chronic
May be more of a benefit in COPD

Question 15

What is Cromoglicate?

Answer 15

Mast cell stabiliser
May be used as prophylaxis in mild and exercise induced asthma

May precipitate asthma

Question 16

What are leukotriene receptor antagonists?

Answer 16

Oral montelukast
Zafirlukast

Block effects of cysteinyl leukotrienes in airways by antagonising CystLT1 receptor

Question 17

What are anti IgE monoclonal antibodies?

Answer 17

Omalizumab
May be used in highly selected px with persistent allergic asthma

SC injection every 2-4 weeks
Specialists prescribe only

Question 18

What are side effects of Aminophylline?

Answer 18

Increased pulse
Arrhythmias
Nausea
Seizures

Question 19

Respiratory stimulant drugs

Answer 19

Used in acute exacerbations of COPD if repeated no response

Doxapram 1.5-4mg/min IV if not suitable for mechanical ventilation

Question 20

What are side effects of Doxapram?

Answer 20

Agitation
Confusion
Tachycardia
Nausea