Drug Treatments of Asthma

Question 1

Name 4 advantages of treatment by inhalation

Answer 1

Large Surface area

Good blood flow

Reduced systemic absorption

Proteins not degraded by acids

Question 2

Name 4 disadvantages of treatment by inhalation

Answer 2

Technically difficult

Small proportion of dose absorbed

Mucus reduces absorption

Cough and local effects

Question 3

What is step 1 of the treatment ladder of asthma?

Answer 3

Short acting β agonist

Question 4

What is step 2 of the treatment ladder of asthma?

Answer 4

Low dose inhaled steroid.

Question 5

What is step 3 of the treatment ladder of asthma?

Answer 5

a) Higher dose inhaled steroid
b) Leukotriene antagonist
c) Long acting β agonist

Question 6

What is step 4 of the treatment ladder of asthma?

Answer 6

High dose inhaled steroid

Consider theophylline.

Question 7

What is step 5 of the treatment ladder of asthma?

Answer 7

Daily oral steroids

Question 8

What is the mechanism of smooth muscle relaxation?

Answer 8

Question 9

Explain the mechanism of β2 agonists in asthma treatment.

(3 marks)

Answer 9

They increase cAMP production → relax bronchial smooth muscle.

Also inhibits release of inflammatory mediators

Increases mucus clearance

Question 10

What are the side effects of β2 receptor agonists?

Answer 10

Tremor

Tachycardia

Hypokalaemia

Question 11

How do corticosteroids work in the treatment of asthma?

Answer 11

Reduce the number of immune cells

Reduce inflammatory mediators

Reduce vascular permeability

Question 12

Side effects of inhaled steroids

Answer 12

Systemic effects avoided

Local effects:

Sore throat

Candida (fungal infections, many in gut)

Hoarse voice

Question 13

How do long acting β2 receptor agonists work to prolong effects?

Answer 13

They actions are prolonged by the lipid side chain.

Question 14

What is in the following combination inhalers?

Fostair

Seretide

Symbicort

Answer 14

Fostair = Beclometasone + Formoterol

Seretide = Fluticasone + Salmeterol

Symbicort = Budenoside + Formoterol

Question 15

How do leukotriene receptor antagonists work?

Answer 15

Leukotriene blocked from receptor →

reduces wheeze and bronchoconstriction

reduces eosinophil and basophil influx

reduces mucus infiltration and microvascular leakage

Question 16

How do xanthines work in asthma treatment?

Answer 16

Xanthines inhibit phosphodiesterase → cAMP cannot be broken down to AMP

Also reduction in synthesis and secretion of inflammatory mediators

Question 17

Name two xanthines used for asthma treatment.

Answer 17

Theophylline, Aminophylline

Question 18

Name a disadvantage of xanthines.

Answer 18

Narrow therapeutic window

Question 19

With good technique, what percentage of inhaled drugs reaches the lung? and for bad technique?

Answer 19

20% for good; 5% for bad

Question 20

What are the values for the following in Mild asthma:

PEFR

Pulse

RR

Sats

Answer 20

PEFR = >75%

Pulse = <100bpm

RR<20

Sats >96%

Question 21

What are the values for the following in Moderate asthma:

PEFR

Pulse

RR

Sats

Answer 21

PEFR = 50-75%

Pulse = 100-110

RR = 20-25

Sats = >92%

Question 22

What are the values for the following in severe asthma:

PEFR

Pulse

RR

Sats

Answer 22

PEFR = 33-55%

Pulse = >110

RR = >25

Sats <92% on air

Unable to talk full sentences

Question 23

What are signs for life threatening asthma? (7 signs)

Answer 23

PEFR = <33%

Confused

Acidotic

Normal/high pCO2 (hypercapnic)

Hypoxic

Bradycardia/hypotension

Poor respiratory effort