Asthma

Question 1

Asthma

Answer 1

Recurrent reversible airway obstruction
Obstructive lung disease
Inflammatory disease
Immediate: Bronchospasm
Delayed: Bronchospasm, vasodilation, oedema, mucous secretion

Question 2

Asthmatic Immune Response

Answer 2

Normal: Th1 inhibits Th2 via IFN-Y
Asthma: Th2 releases cytokines (IL-13/14) which recruit cells
Il-13 induces asthmatic response directly
Mucous production, bronchospasm, oedema

Question 3

Bronchodilator Classes

Answer 3

Beta 2 Agonists
PDE Inhibitors
Atropine like substances

Question 4

Anti-Inflammatory Classes

Answer 4

Cromoglycate
Glucocorticoids
Leukotriene pathway modulators
IgE Antibodies

Question 5

Beta-2 Agonists

Answer 5

First Choice
Salbutamol, inhaled, duration 3-5 hours
LABAs- given with corticosteroids, Salmeterol, Formoterol, lipid soluble
Activate MLCP
Decr. Ca2+
Incr. K+
Inhibit mediator release from Mast Cells

Question 6

Xanthines

Answer 6

PDE Inhibitors- Theophylline
Increase cAMP
Inhibition of PDEVI in T Cells- anti-inflammatory
Long acting, oral, slow release
Narrow therapeutic index, metabolised by CYP450
SE: N and V, insomnia, cardiac arrhythmias

Question 7

Anticholinergics

Answer 7

Ipratropium
Block muscarinic receptors on smooth muscle and glands
Administered by inhalation
SE: Glaucoma, dry mouth

Question 8

Cromoglycate

Answer 8

Phrophylactic- prevents immediate asthma
More effective in younger
Inhaled
Mast cell stabiliser, activates natural “Turn-Off” via membrane protein phosphorylation

Question 9

Glucocorticoids

Answer 9

Effective in late phase- Beclomethasone
Mechanism: anti-inflammatory
Lipocortin synthesis inhibits Phospholipase A2, decreasing LTs
Reduced cytokine formation and inflammatory cell activation
Given with LABAs and acute sever asthma
SE: Cataracts, immunosuppression, oral candidiasis

Question 10

Leukotriene Pathway

Answer 10

LTC4 and D4 cause bronchoconstriction and mucous secretion
Zileuton- Inhibits 5-LOX
Zafirlukast, montelukast- Block Cys-LT1 receptors
Both oral

Question 11

Anti-IgE MAb

Answer 11

Omalizumab, humanised mouse anti-IgE Ab
Binds IgE at Fc
MOA: Decrease circulating IgE and blocks IgE binding at Mast Cells
Do not cross link- no anaphylaxis
Down regulates Fc receptors on Mast Cells reducing Th2 stimulation
Subcutaneous