Cough and Cold drugs / Respiratory drugs

Question 1

name the 2 categories of anti-asthmatics and the drug classes with drug names

Answer 1

controller (anti-inflammatory)

• inhaled corticosteroids e.g. fluticasone
• leukotriene pathway inhibitor e.g. montelukast/zileuton
• anti-IgE monoclonal antibody e.g. omalizumab
• anti-IL5/IL-4R monoclonal antibody e.g. other zumabs

reliever (bronchodilator)

• b2 agonists (SABA, LABA, ultra LABA) e.g. salbutamol, salmeterol/formoterol, idacaterol
• muscarinic antagonists e.g. ipratropium bromide, tiotropium bromide
• methylxanthine e.g. theophylline

Question 2

fluticasone

drug class + MOA + uses + side effects

Answer 2

Drug class: inhaled corticosteroids (controller)

MOA: nuclear receptor to decrease transcription of inflammatory cytokines

Uses: first line prophylactic for asthma (inhaled)

Side effects: oropharyngeal candidiasis, throat infections, easy bruising (thrombocytopenia)

Question 3

montelukast/zileuton

drug class + MOA + uses + side effects

Answer 3

Drug class: leukotriene pathway inhibitor (controller)

MOA: inhibits5- lipo oxygenase enzyme to prevent production of leukotrienes

Uses: more for aspirin-induced asthma

Side effects: shunting to other pathways

Question 4

omalizumab

drug class + MOA + uses

Answer 4

Drug class: anti-IgE monoclonal antibody (controller)

MOA: IgE is an important antibody in immunity and inflammation and hence binding to it to inhibit it can prevent stimulation of immunity/inflammation (such as prevention of mast cell degranulation)

Clinical uses: prophylaxis and treatment of chronic asthma

Question 5

other zumabs 
(drug class + MOA + uses)

Answer 5

Drug class: anti-IL5/IL4R monoclonal antibody (controller)

MOA: binds to the cytokine sth inhibit immunity-induced inflammation

clinical uses: treatment for severe asthma that does not respond to the above

Question 6

mechanism of action of B2 agonists

Answer 6

increase adenyl cyclase and cAMP = decrease calcium concentration = smooth muscle relaxation

also has additional functions: mast cell stabilisation + increase mucociliary clearance

Question 7

salbutamol

drug class + uses + duration of action

Answer 7

Drug class: short acting BA

Uses: bronchiole smooth muscle relaxation

Duration of action: rapid (3-6 hours)

Question 8

salmeterol/formoterol (drug class + MOA + duration of action)

Answer 8

Drug class: long acting BA

MOA/uses: maintenance and prevention

Duration: taken twice daily (12 hours)

Question 9

indacaterol (drug class + MOA + duration of action)

Answer 9

Drug class: ultra long acting BA

MOA/uses: only used in COPD (together with tiotropium bromide as a bronchodilator)

Duration: once daily (24 hours)

Question 10

ipratropium bromide/tiotroprium bromide (drug class + MOA + uses + side effects)

Answer 10

Drug class: muscarinic inhibitor

MOA: inhibit m3-mediated bronchoconstriction and reduce secretions

Uses: tiotropium is a first-line bronchodilator in COPD (along with indacaterol)

Side effects: unpleasant taste and dry mouth (affects compliance) + urinary retention in elderly

Question 11

theophylline (drug class + MOA + side effects)

Answer 11

Drug class: methylxanthines

MOA: inhibits PDE4 enzyme, resulting in cAMP accumulation and hence broncho-relaxation (similar to B2 agonist)

also has additionally anti-inflammatory effects on mast cells and T cells (once again, similar to B2 agonists)

Side effects: has a narrow therapeutic window + drug-drug interaction with antimicrobials

Question 12

first line asthmatic therapy when there is an attack

Answer 12

ICS-formoterol is the preferred reliever of choice

double whammy in one puff:

• controller: inhaled corticosteroid
• reliever: formoterol (rapid acting that lasts for 3-6 hours)

Question 13

maintenance therapy for asthma

Answer 13

ICS-LABA with SABA salbutamol for reliever when necessary

Question 14

do we regularly use indacaterol?

Answer 14

no, as it is a long-acting BA and is only used for COPD (along with tiotroprium bromide)

Question 15

what do we give if asthma is poorly controlled (even with ICS-LABA)?

Answer 15

we give theophylline as an adjunct therapy

Question 16

why do we have to give ICS along with LABA for long-term maintenance therapy?

Answer 16

over time, LABA can cause tolerance by down regulation of receptors and if an attack was to occur, the patient would not be susceptible to salbutamol = increased risk of athsma-related death.

hence we have to give ICS in order to increase B2 receptor level

Question 17

what are the drug classes for cough/cold?

Answer 17

to reduce blocked nose, you make the mucus more watery and you increase the excretion of it. worse come to worse, you try to decrease production of mucus.

make mucus more watery:

• expectorants
• mucolytics

increase excretion of mucus:

• decongestants
• mucokinetics

decrease production of mucus:

• antihistamines
• mucoregulators

to reduce cough, you suppress the cough center.

suppress cough center:
- suppressant

Question 18

what are the drug examples for each cough/cold drug class?

Answer 18

suppressant:
codeine, dextromethorphan

expectorant:
guaiphenesin

mucolytic:
aerosolised N-acetylcysteine
carbocisteine

decongestant:
pseudoephedrine
oxymetazoline

B2 agonists:
salbutamol, salmeterol, ambroxol

anti-histamine:
1st gen - diphenhydramine
2nd gen - cetirizine. loratadine, fexofenadine

muscarinic inhibitor:
ipratropium bromide, tiotropium bromide

Question 19

codeine (drug class and MOA)

Answer 19

drug class: suppressant/antitussive

MOA: works as an opioid receptor agonist and suppresses cough center in brainstem

Question 20

dextromethorphan (drug class and MOA)

Answer 20

drug class: suppressant/antitussive

MOA: works as an opioid receptor agonist and suppress cough center in brainstem

Question 21

side effect of suppressants e.g. codeine and dextromethorphan

Answer 21

shuts down GIT and urinary tract - constipation/urinary retention

addition as codeine is converted to morphine in the body

Question 22

contraindications of codeine and dextromethorphan

Answer 22

codeine is not given in those < 18 due to addiction problem but dextromethorphan is not given to children < 4 due to sedation, GI disturbance and CVS disturbance

Question 23

guaiphenesin (drug class and MOA)

Answer 23

Drug class: expectorant

MOA: increases water content of mucus to make it looser and easier to expel

Question 24

contraindication of guaiphenesin

Answer 24

cannot be used in young children < 2 years old

Question 25

aerosolised n-acetylcysteine and carbocisteine (drug class and MOA)

Answer 25

Drug class: mucolytics

MOA: breaks down disulphide bonds and makes mucus less viscous

additional anti-inflammatory effect

Question 26

pseudoephedrine/oxymetazoline (drug class and MOA)

Answer 26

Drug class: decongestant

MOA: a1 agonist; increase vasoconstriction of nasal passage

Question 27

diphenhydramine/cetirizine/fexofenadine (drug class and MOA)

Answer 27

Drug class: anti-histamine

MOA: H1 antagonist; decrease secretions and vasodilator

Question 28

ipratropium bromide/tiotropium bromide (drug class and MOA)

Answer 28

Drug class: muscarinic antagonists

MOA: m3 antagonist; decrease mucus hyper secretion (does not inhibit basal secretion)