Respi - cough and cold

Question 1

causes of common cold

Answer 1

upper respiratory tract infection

• rhinovirus
• coronavirus
• resp syncytial virus (RSV)

Question 2

groups of drugs for common cold

Answer 2

• H1 antihistamines
• Paracetamol
• NSAIDs (ibuprofen)
• Cough: cough suppressants, mucoactive agents
• Nose: nasal decongestions

Question 3

Cough suppressant drug

Answer 3

for dry coughs - no mucus
opiates
- morphine
- codeine*
- hydrocodone* 
dextromethorphan (corticosteroids)

Question 4

opitates MOA

Answer 4

bind to opioid receptors found in cough centre in brain
- codeine: “gold standard for cough suppression”
prodrug, converted to morphine by CYP2D6
-> if CYP2D6 has poor metabolism, codeine will be ineffective
- hydrocodone: synthetic active opioid -> more ADR

Question 5

hydrocodone ADR + CI

Answer 5

risk of SE??
- sedation, constipation, nausea and vomitting, addiction, respiratory depression
CI: <18 yrs

Question 6

dextromethorphan MOA

Answer 6

non-narcotic codeine analogue
-> no CNS effects: no analgesia/ addiction
does not bind to opioid receptors
- binds to NMDA receptors, blocking Na+ and Ca2+ influc
- activates Sig-1 receptors, channel Ca2+ into mitochondria
reduces cough severity

Question 7

dextromethorphan CI

Answer 7

<4 yrs

Question 8

4 groups of mucoactive agents

Answer 8

• mucolytics - mucus thinning
• expectorants - induce cough
• mucokinetics - mucus transport
• mucoregulators - suppress mucus secretion

Question 9

mucolytic drug (mucus thinning)

Answer 9

1. NAC: N-acetylcysteine
   aerosolised
2. carbocisteine

Question 10

NAC MOA

Answer 10

severes bonds in mucus -> depolymerise mucin polymers -> decrease viscosity of sputum
also has anti-inflammatory effects - neutrophil infiltration
used in hypersecretion of mucus in: COPD/ asthma/ cystic fibrosis/ URTI

Question 11

carbocisteine MOA

Answer 11

break disulphide bonds in mucus, reduce viscosity
decrease adhesion of virus to ciliated epithelium
used in: COPD/ asthma/ cystic fibrosis/ URTI

Question 12

expectorant drug (induce cough)

Answer 12

guaifenesin

Question 13

guaifenesin MOA

Answer 13

liquefy sputum in the airways - decrease viscoelasticity and adhesiveness of mucus
suppress mucin production + promote mucociliary transport
used when there is hypersecretion of mucus

Question 14

guaifenesin ADR

Answer 14

nausea and vomiting

kidney stones - must remain hydrated

Question 15

mucoregulator drugs (suppress mucus production)

Answer 15

• anticholinergics: ipratropium/ tiotropium bromide

- macrolides: erythromycin, clarithromycin, azithromycin (ACE)

Question 16

anticholinergic agents MOA as mucoregulators

Answer 16

blocks inflammation M3 activation of submucosal glands, decrease airway SM contraction
decrease stimulation of mucus secretion

Question 17

macrolides MOA as mucoregulators

Answer 17

• inhibit MUC5AC gene expression
• inhibit IL-13 induced mucus production
• inhibit neutrophil chemotaxis

Question 18

nasal decongestions drugs

Answer 18

• sympathetic: phenylephrine, pseudoephedrine - intranasal/oral
• fast-acting: oxymetazoline, xylometazoline, naphazoline (-zoline) - intranasal

Question 19

nasal decongestions MOA

Answer 19

vasoconstriction of superficial blood vessels -> decrease nasal swelling in mucosa

Question 20

nasal decongestions ADR + CI

Answer 20

hypertension, tachycardia - cause of the vasoconstriction
insomia, restlessness, tremors
nasal irritation
may have rebound nasal congestion after 3 days
CI: heart disease/ DM/ HTN

Question 21

mucokinetic drugs

Answer 21

SABA, LABA (beta agonists)
ambroxol
bromhexine

Question 22

ambroxol MOA (4 effects)

Answer 22

• promotes mucus clearance
• increase ciliary movement
• stimulate surfactant (prevents mucus from sticking to alveolar and bronchial walls)
• decrease cytokines - decrease inflammation