Management Of Cough

Question 1

What is cough?

Answer 1

Useful physiological mechanism that serves to clear the respiratory passages of foreign material and excess secretions

Question 2

What underlying causes can you look for when treating a cough

Answer 2

• GERD
• Infection
• Worms
  -Drugs

Question 3

List the 5 classes of anticough agents

Answer 3

• Antitussive
• Antihistamines
• Pharyngeal demulcents
• Expectorants
• Mucolytics

Question 4

What is the MOA of antitussives

Answer 4

Inhibits cough reflex by suppressing cough center in medulla or peripheral receptors

Question 5

Drugs classified as antitussives

Answer 5

• Codeine central acting
• Pholcodine and Noscapine
• Dextromethorphan
• Benzonatate

Question 6

Disadvantages of antitussives

Answer 6

-Addiction
-Drowsiness
- Constipation
- Respiratory depression

Question 7

Difference between codeine-central acting drugs and pholcodine

Answer 7

-Pholcodine is longer acting than codeine
- Do not have analgesic nor addictive properties
- Do not cause constipation
- Does not interfere with mucociliary movement

Question 8

Which anticough agent should be avoided in children and asthmatics

Answer 8

Codeine and Pholcodine

Question 9

What is the most widely used cough suppressant

Answer 9

Dextromethorphan

Question 10

What form of administration is available for Dextromethorphan

Answer 10

Tablets
Syrup
Spray forms

Question 11

What receptors are targeted by Dextromethorphan

Answer 11

NMDA receptors

Question 12

What is the therapeutic use of Dextromethorphan

Answer 12

Temporary relief of cough caused by minor throat and bronchial irritation

Question 13

What cough suppressant removes sensation

Answer 13

Benzonatate

Question 14

Which is the drug of choice to suppress cough in patients undergoing bronchoscopy

Answer 14

Benzoate

Question 15

What is the MOA of antihistamines

Answer 15

They are H1 receptor antagonists
They target histamine receptors of the smooth muscle.

Question 16

List first generation H1 receptor antagonists

Answer 16

Diphenhydramine
Chlorpheniramine
Cyclizine
Promethazine
Cyproheptadine
Ketorifen

Question 17

List second generation H1 receptor antagonists

Answer 17

Cetirizine
Fexofenadine
Loratadine
Desloratadine
Olopatadine
Azelastine

Question 18

What are the major differences between first and second generation antihistamines

Answer 18

First generation Antihistamines block both histaminic and muscarinic receptors as well as passing the BBB

Second generation Antihistamines mainly block histaminic receptors and do not pass the BBB

Question 19

Why are second generation antihistamines preferred over first generation

Answer 19

Due to their favourable efficacy/safety ratio and lack of cholinergic and sedative side effects

Question 20

Half life of first generation antihistamines

Answer 20

4 to 12 hrs

Question 21

Half life of second generation antihistamines

Answer 21

12 to 24 hrs

Question 22

What are other therapeutic uses of antihistamines

Answer 22

• H1 blockers have major application in allergies of the immediate type
• Used as anti motion sickness drugs
• Morning sickness in pregnancy (Doxylamine and pyridoxine)
• Appetite stimulants

Question 23

List pharyngeal demulcents

Answer 23

Lozenges
Linctus
Honey
Cough drops
Liquorice

Question 24

What is the MOA of pharyngeal demulcents

Answer 24

Used when cough arises due to irritation above larynx by protecting irritant receptors in mucosa or respiratory tract

Produce soothing effect on inflamed mucosa

May contain mild local anesthetics

Question 25

What is the MOA of expectorants

Answer 25

Increase volume of bronchial secretion Reduce the thickness, adhesiveness, and surface tension of mucus so cough becomes less tiring and productive

Question 26

What are the two classifications of expectorants

Answer 26

- Directly acting on RT cells ( Guaifenesin) - Reflex acting: stimulate the RT secretions by secreting gastric mucosa (Ammonium salt, iodides, some bitter herbs like ipecac)

Question 27

What is the MOA of mucolytics

Answer 27

Breakdown mucus

Question 28

Examples of mucolytics

Answer 28

Bromohexine Acetyl cysteine

Question 29

What are bland aerosols

Answer 29

Drugs that dilute mucus molecules and are known as wetting agents

Question 30

Types of bland aerosols

Answer 30

- Sterile and distilled water (humectant, dense aerosols and asthmatics) - Normal (isotonic saline) - Hypertonic saline - Hypotonic saline

Question 31

MOA of bland aerosols

Answer 31

Disruption of disulfide bonds -Acetyl cysteine breaks the bonds by substituting a sulfhydryl radical

Question 32

Hazards of acetylcysteine

Answer 32

- Bronchospasm - Increase mucus secretion - Do not mix with antibiotics in the same nebuliser - Nausea and vomiting (smells like rotten eggs) - Alteration of pH - Proteolysis

Question 33

Common side effects of pulmozyne

Answer 33

- Voice alteration - Pharyngitis/ laryngitis - Rash

Question 34

MOA and side effects of bromohexine

Answer 34

Liberates lysosomal enzymes which digest mucopolysaccharides, hence decrease viscosity of sputum Side effects: rhinorrhea and lacrimation

Question 35

MOA of amiloride

Answer 35

It is a sodium channel blocker. In cystic fibrosis, Na+ is absorbed in the epithelium along with H2O, leaving the mucus thick and dehydrated. By blocking sodium absorption, dehydration of the mucus is prevented.

Question 36

MOA of denusfosol tetrasodium

Answer 36

Enhances mucosal hydration and mucus clearance by activating Cl- secretion and inhibiting epithelial Na+ transport