(6.2) Anti-asthmatics

Question 1

Briefly describe the immediate phase asthmatic inflammatory response.

Answer 1

Allergen + IgE -> Mast cell -> Histamine -> Bronchospasm

Question 2

Briefly describe the late phase asthmatic inflammatory response.

Answer 2

Co-release of mediators -> Leucocytes:

• > Basement membrane oedema
• > Destruction of epithelium -> expose allergen receptors
• > Mucus production

Question 3

What are the SNS and PNS receptors on airways? Each list their actions.

Answer 3

SNS - Beta 2 adrenoreceptors:

• Bronchodilation
• Mast cell inactivation
• Increased mucociliary clearance

PNS - M3 Muscurinic receptors:

• Bronchoconstriction
• Goblet cell production

Question 4

During what times of the day does asthmatic symptoms get worse? Why?

Answer 4

• Night / Early morning

- PNS activation & coldness

Question 5

Briefly describe the mechanism of action of bronchodilators.

Answer 5

Beta2 agonist -> +GsA -> +Adenyl Cyclase -> +PKA & -Ca2+ in airways -> smooth muscle relaxation

Question 6

Name one bronchodilator and its route of prescription:

• Short acting, fast onset
• Short acting, slow onset
• Long acting, fast onset
• Long acting, slow onset

Answer 6

• Short acting, fast onset: Inhaled Salbutamol
• Short acting, slow onset: Oral Salbutamol
• Long acting, fast onset: Inhaled Formoterol
• Long acting, slow onset: Inhaled Salmoterol

Question 7

In what conditions is bronchodilator contraindicated and why? What alternative choice of drugs can be used (name 2 examples).

Answer 7

• IHD
• E.g. Propanolol, a beta agonist acts on both B1 & B2 receptors -> increased heart workload
• M3 antagonists e.g. Ipatropium & Piotropium

Question 8

What does frequent use of Bronchodilator have on its anti-asthmatic effects?

Answer 8

Frequent use -> +Mast cell degranulation -> +Histamine Production -> reduced bronchodilator effect

Question 9

What is the mechanism of action of Corticosteroids have on Asthma?

Answer 9

Suppress Mast cell production -> effectively treat Eosinophillic asthmatics

Question 10

What are the ADRs of Corticosteroids specifically have on airways due to its route of prescription.

Answer 10

Direct Inhalation:

• > Croaky voice
• > Sore throat
• > Thrush

Question 11

What substances are contained in combined inhaler? Name a drug.

Answer 11

• Long acting beta 2 agonist
• Corticosteroids
• Symbicort

Question 12

List 3 ADRs of Anti-muscurinic.

Answer 12

• Urine retention
• Dry mouth
• Glaucoma

Question 13

Name an example of Leukotriene receptor antagonist.

Answer 13

Montelukast

Question 14

How does a Theophylline work?

Answer 14

Adenosine antagonist

Question 15

List 4 ADRs of Bronchodilators.

Answer 15

• Palpitations
• Tremors
• Tachycardia
• Hypokalaemia

Question 16

What type of autonomic control is dominant in maintaining airway muscle tone?

Answer 16

PNS

Question 17

Due to common ADRs of Aminophylline, it is less used, suggest 3 ADRs.

Answer 17

• Nausea
• Psychomotor agitation
• Reflux

Question 18

Describe the pathology of COPD.

Answer 18

Cigarette smoke & other irritants -> Macrophages release Cytokines & Mediators:

• > Fibrosis of small airways
• > Alveolar wall destruction (Emphysema)
• > Mucus hypersecretion