Asthma pharmacology

Question 1

What are the two phases in an asthma attack?

Answer 1

1. early phase - Bronchoconstriction - due to release of spasmogens (e.g. histamine etc.)
2. late phase - bronchoconstriction, inflammation, hyperreactivity, hyperreactivity, hypersecretion.

This is due to infiltration of Th2 cells, eosinophils, monocytes and macrophages because of chemoattractants, secreted by mast cells upon antigenic stimulation.

Question 2

What does activation of M3 receptors in airways cause?

Answer 2

bronchoconstriction

increased secretions

Question 3

What is the effect of prostaglandins in inflammation?

Answer 3

vasodilation

bronchoconstriction

Question 4

What is the effect of leukotrienes in asthma?

Answer 4

chemotaxis, increased permeability, bronchoconstriction.

Question 5

What is the effect of a beta 2 agonist on the airways?

Answer 5

Bronchodilation

decrease in secretions

Question 6

What is the mechanism of ipratropium?

Answer 6

Acetylcholine antagonist.

Stops ACh binding to M3 receptors, this causes relaxation of trachealis muscle and therefore bronchodilation.

Question 7

What is the mechanism of salbutamol?

Answer 7

SABA
short acting beta2 agonist

Causes bronchodilation and a decrease in mucus secretions

often first line in treating asthma.

Question 8

How does the residual volume change in an asthma pt?

Answer 8

increase

Question 9

How do we measure FEV?

Answer 9

forced expiratory volume

spirometer

Question 10

Why is the FEV curve biphasic?

Answer 10

initial stage = release of chemotaxins by mast cells cause infiltration of monocytes, macrophages etc and cause a delayed inflammation and hypersensitivity.

Question 11

Give an example of a long acting beta antagonist

Answer 11

salmeterol

Question 12

name 2 muscarinic antagonists used in asthma tx?

Answer 12

ipratropium

tiotropium

Question 13

What are some of the side effects of muscarinic antagonists?

Answer 13

Nausea, heartburn, constipation

dry mouth

difficulty urinating

eye irritation

tachycardia

Question 14

What is the use of theophylline?

Answer 14

asthma, bronchodilator

Question 15

What is theophylline mechanism of action?

Answer 15

Inhibits phosphodiesterase, leading to increased cAMP levels and bronchodilation.

Question 16

What is the function of leukotriene receptor antagonists?

Answer 16

bronchodilation

Question 17

give an example of a leukotriene antagonist which can be used in asthma tx?

Answer 17

montelukast

Question 18

Give an example of glucocorticoids used in asthma treatment

Answer 18

prednisolone

hydrocortisone

beclomethasone

Question 19

What is the mechanism of action of glucocorticoids?

Answer 19

Reduce cytokine release

stop production of annexin-1 which stops the production of prostaglandin and leukotrienes by inhibiting phopholipase A2.

Question 20

What are some side effects of using glucocorticoids?

Answer 20

HPA axis suppression (dependence on exogenous
glucocorticoids)

Gastric ulcers

Cushings symdrome

Infection

Question 21

Give an example of some drugs which can cause asthma attacks

Answer 21

Beta blockers - propanolol, atenolol

Anti-cholinesterases - neostigmine

NSAIDS such as aspirin.

Question 22

How can NSAIDS cause an asthma attack?

Answer 22

Inhibit COX, so all of the PGH2 is then converted into leukotrienes via lypoxygenase.