Respiratory Pharmacology

Question 1

why do we cough

Answer 1

protective reflex: prevents lungs from aspiration

common symptom of respiratory disease

Question 2

what are the two types of cough

Answer 2

useless and useful

Question 3

what is a useless cough, eg, should it be suppressed

Answer 3

persistent and unproductive: dry cough
eg asthma, oesophageal reflux
yes it should be suppressed using antivusses - must treat underlying cause tho

Question 4

what is a useful cough, eg and should it be suppressed

Answer 4

expels secretions such as sputum in chest infection

it should not be suppressed unless it is exhausting the patient or painful

Question 5

what is the mechanism of a cough

Answer 5

cough receptors or lung irritant receptors
cough centre in the medulla
vagal stimulation leading to cough

Question 6

what can you use to suppress dry cough

Answer 6

afferent side: reduce stimuli

efferent side: medullary centre - using opioids, non opioids sedatives

Question 7

how do you reduce stimuli on the afferent side

Answer 7

Above larynx: Linctuses (demulscents)
Below larynx: Steam inhalation, Nebulised local anaesthetics
Treat cause: stop smoking

Question 8

how do you reduce stimuli on the efferent side

Answer 8

Opiods (codeine, methadone, pholcodeine)
Non opiods (dextromethorphan, noscapine)
Sedatives: diphenhydramine, chlorpheniramine

Question 9

what is the difference between mucolytics and expectorants

Answer 9

mucolytics make it easier to remove sticky substances such as DNA build up in CF - decrease the viscosity
expectorants increase the volume of secretion but with not added value

Question 10

what are the most common causes of chronic cough

Answer 10

Upper airways cough syndrome (post nasal drip)  Bronchial Asthma
Chronic Obstructive Pulmonary Disease
Gastroesophageal ref lux disease

Question 11

what are the 4 types of bronchial asthma

Answer 11

asthma associated with allergic reactions
asthma not associated with specific allergen
exercise induced asthma
asthma associated with chronic obstructive disease

Question 12

describe the process of allergy mediated asthma

Answer 12

1 - antigen detected by APC which presents it to Th2 which targets B cell to produce IgE which activates mast cell to produce chemical mediators of inflammation
2 - antigen directly stimulates mast cell

Question 13

what are the different treatments for asthma

Answer 13

Non specific reduction of bronchial hyperactivity: Nonpharmacological: Stopsmoking,weightreduction  Pharmacological: Corticosteroids

 Dilatation of narrowed bronchi:
 Mimicking dilator neurotransmitter: Sympathomimetics  Direct acting bronchodilators: Methylxanthines
 Blockade of constrictor transmitter: Anticholinergics

Preventionofreleaseof transmitter  Mast cell stabilisers

Antagonism of released transmitter:  Leukotriene receptor antagonists

Question 14

what are the non-specific reductions of bronchial hyperactivity

Answer 14

corticosteroids
anti-inflammatory - decrease oedema
reduced bronchial activity - reduce exacerbations (do not relax bronchiole smooth muscle)

Question 15

what are the inhaled vs tablet corticosteroids

Answer 15

brown inhaler
beclomethasone
fluticasone
oral corticosteroids - prednisone (for severe asthma)

Question 16

what are the adverse effects of corticosteroids

Answer 16

iatrogenic cushing syndrome
inhibition of hypothalamic pituitary axis
oropharyngeal candidadiasis
hoareness

Question 17

what are mast cell stabilisers

Answer 17

Cromolyn sodium , Nedocromil sodium
 Inhibit release of mast cell mediators
 Administered by inhalation and very poorly absorbed
 No effect on bronchial smooth muscle  No use in acute bronchospasm
 Only valuable if taken prophylactically
 Main uses: Allergic rhinitis, allergic conjunctivitis
Sideeffects: Throatirritation,cough,dermatitis, myositis, gastroenteritis

Question 18

what are leyukotrine pathway inhibitors

Answer 18

check home screen

Question 19

what are inhibitors of leukotriene synthesis

Answer 19

Inhibit 5-lipoxygenase

 Zileuton (discontinued) – liver toxicity

Question 20

what are inhibitors of leukotriene receptors

Answer 20

inhibit binding of leukotriene to receptor

montelukast

Question 21

what are leukotriene receptors antagonists and give example

Answer 21

Uses
 Allergen induced asthma, Exercise induced asthma  Reduce frequency of exacerbations
 Given orally: Good for children
 Not effective in acute asthma
 Minor adverse effects :
 Headache, Gastritis, Flu-like symptoms, CS syndrome
 Montelukast : Commonly used  Cost - cheap

Question 22

what substances affect bronchial tone

Answer 22

beta agonists and theophylline cause bronchodilation

Question 23

what is the blue inhaler

Answer 23

act via B2 agonists
Short acting (3-6 hours) SABA
 Albuterol~Salbutamol, terbutaline, fenoterol, metaproterenol
 Long acting (12 -24 hours) LABA  Salmetrol, formetrol
 Non selective  Adrenaline

Question 24

what is the most commonly used blue inhaler

Answer 24

salbutamol

Question 25

when is adrenaline used

Answer 25

in emergency situations as subcutaneous injection

Question 26

what are some side effects of B2 receptors agonists

Answer 26

Heart- Palpitation, tachycardia, cardiac arrhythmias  Muscle- Tremor
 Others - Restlessness, nervousness, hypokalemia

Question 27

what are methylxanthines and what are some adverse effects

Answer 27

Administered oral or i.v..
 Adjuvant therapy in asthma
 Adverse effects:
Palpitations, cardiac arrhythmia,hypotension
 Gastrointestinal irritation ( increased acid production)  Diuresis, hypokalemia
 Anxiety, headache, seizures
 Therapeutic window (55 -110 mmol/l)

Question 28

what are two examples of methylxanthines

Answer 28

Theophylline
 Oral : rapid and complete absorption
 90 % metabolised, saturable metabolism  Adjuvant therapy in Asthma
 SR Theophylline
 Aminophylline
 Intravenous
 Used in severe asthma
 Loading dose   infusion

Question 29

how do anticholinergic agents help asthma

Answer 29

act via inhibiting muscarinic receptors - M3

Question 30

give examples of muscarinic antagonists and what it does

Answer 30

tiotropoium - long acting

inhibit effects of vagus nerve stimulation

Question 31

what are some adverse effects of muscarinic antagonists

Answer 31

Airway irritation
 Anticholinergic effects
 GI upset, urinary retention

Question 32

what other drugs affect asthma airways

Answer 32

anti IgE monoclonal antibodies
ketoifen
magnesium
ketamine

Question 33

how do monoclonal antibodies affect asthma

Answer 33

Omalizumab
 Inhibits binding of IgE to mast cells
 Repeated administration
 Lessens asthma severity
 Reduces magnitude of response  Reduced requirement of steroids
 Very expensive

Question 34

how does ketotifen affect asthma

Answer 34

Histamine receptor antagonist (H1)  Some anti-asthma effect
 Side effects: drowsiness etc
 No proven benefit

Question 35

how does Mg affect asthma

Answer 35

Patients who fail to respond to inhaled bronchodilators  By intravenous infusion

Question 36

how does ketamine affect asthma

Answer 36

Anaesthetic agents
 Bronchodilator properties
 No role in routine management
 Used in life-threatening or near fatal asthma

Question 37

what are the similarities and differences between asthma and COPD

Answer 37

Asthma – Reversible airway obstruction
 COPD – Incompletely reversible airway obstruction
Both characterised by airflow limitation  COPD occurs in older patients
 COPD progressive worsening over age