Allergic Rhinitis, cough and cold

Question 1

Should you take Antibiotics if you have viral common cold symptoms?

Answer 1

No, It does not help, it increases antibiotic resistance instead.

Question 1

Explain the process of allergic rhinitis re: pollen

Answer 1

1) Exposure to pollen
2) plasma cells release IgE.
3) IgE antibodies binds to mast cells
4) Pollen binds to IgE antibodies and release histamine
5) histamine cause allergy symptoms

Question 2

Why is the first generation of antihistamines eg. promethazine not an ideal choice ?

Answer 2

drugs such as promethazine, diphenhydramine and chlorpheniramine are more sedating and have more ANS block

Question 3

Why is the second generation better than the first generation antihistamine?

Answer 3

It has improved selectivity for H1 histamine receptors.
Reduced lipophilicity and greater p-glycoprotein efflux pump affinity and so reduced CNS effect.

Question 4

Which drug should you take if you are working In jobs where wakefulness is critical?

Answer 4

Fexofenadine and loratidine

Question 5

how to administer antihistamines?

Answer 5

oral, max serum levels at 1-2 hours

Question 6

excretion forms of antihistamines

Answer 6

1st : urine
2nd: urine- cetirizine
feces- fexofenadine

Question 7

where are antihistamines metabolised?

Answer 7

1st: liver ( hydroxylation)
2nd: Liver (p450) with active metabolites.

Question 8

List examples of decongestants

Answer 8

Pseudoephedrine
Oxymetazoline
Phenylephrine

Question 9

How to administer decongestants?

Answer 9

oral or intranasal

Question 10

MOA of decongestants

Answer 10

Vasoconstriction of nasal blood vessels
Reduce inflammation and secretion of mucus

Question 11

Which drug is an alpha 1 selective agonist? which is non selective? Which drug cause release of adrenaline to increase?

Answer 11

sympathomimetic agents:
Direct alpha adrenergic agonist:
alpha 1 selective: phenylephrine
Non selective: oxymetazoline

Indirect increase in release of adrenaline: pseudoephedrine

Question 12

List examples of nasal glucocorticoid and their administration route

Answer 12

fluticasone, momethasone

intranasal

Question 13

MOA of nasal glucocorticoid

Answer 13

Anti- inflammatory
Reduce inflammation- reduce congestion and mucus secretion

Question 14

Adverse effects of sympathomimetic agents

Answer 14

1) Rebound congestion with prolonged use of topical nasal decongestant

2) CNS stimulant
- oral decongestant
- restlessness, tremors, anxiety, insomnia, irritability

3) Cardiovascular
- Tachycardia, especially with indirect sympathomimetic agents:
pseudoephedrine
- HTN due to vasoconstriction
- oral

Question 15

Adverse effects of nasal glucocorticoid

Answer 15

Local mucosa dryness and irritation

Question 16

Which sympathomimetic agent is an OTC?

Answer 16

Pseudoephedrine

Question 17

MOA of nasal glucocorticoid

Answer 17

Anti inflammatory:
reduce inflammation, reduce nasal congestion and mucus secretion.

Question 18

What should you prescribe for rhinorrhoea?

Answer 18

Antihistamines:
promethazine, cetirizine, fexofenadine, Loratidine.

Decongestants:
Pseudoephedrine, phenylephrine , oxymetazoline.

Mucoregulators:
Ipatropium, Cromoglicic acid.

Question 19

What should you prescribe for non productive cough that is affecting the patient’s sleep.

Answer 19

Antitussive:
codeine
Diphenhydramine
Dextromethorphan

Question 20

What should you prescribe for productive cough that affect’s the patient’s sleep?

Answer 20

Expectorant:
Guaifenesin

Mucoactive:
Acetylcysteine
Ambroxol

Question 21

Pharmacological class of codeine and its MOA

Answer 21

opiod, acts in CNS to suppress cough

Question 22

Adverse reaction of codeine (opiod)

Answer 22

1) CNS sedation
2) weak opiod but has potential for abuse
3) Respiratory depression
- risk of overdose
- should not occur at normal clinic doses
- risk on patients with severe respiratory insufficiency.

4) Do not combine with CNS depressants eg. XCYP2D6 ultra rapid metabolism

DO NOT USE IN CHILDREN, more sensitive to opiod induced respiratory depression, respiratory centre and liver not fully mature.

NOT RECOMMENDED for those below 18 years old.

Question 23

Adverse effects of Diphenhydramine ( non opiod)

Answer 23

sedative, anticholinergic

Limited effects for cold

Question 24

Adverse effects for Dextromethophan (non opioid)

Answer 24

1) CNS: drowsiness, dizziness, confusion, excitement, insomnia, nervousness 2) Gastrointestinal Nausea, vomiting, stomach pain 3) Abuse potential at high dose - dissociative anaesthetic like effect.

Question 25

Name an example of an expectorant and explain its moa

Answer 25

Guaifenesin It increases production of respiratory tract fluid to liquefy and increase viscosity of tenacious secretions.

Question 26

Adverse effect of guaifenesin?

Answer 26

GI disturbances and nausea

Question 27

What should you take note of when prescribing guaifenesin to children

Answer 27

Caution for those < 6 years old Do not give to those <2 years old.

Question 28

What advice should you give to patients who are taking expectorants?

Answer 28

Do not take it for cough associated with smoking or asthma. To drink more fluid to make the secretions less viscous to protect renal function ( nephrolithiasis)

Question 29

Give an example of mucolytics

Answer 29

Acetylcysteine

Question 30

MOA of acetylcysteine

Answer 30

Free sulfhydryl groups and open disulphide bonds in mucoproteins lower mucus viscosity

Question 31

Adverse reaction of Acetylcysteine

Answer 31

bronchospasm Anaphylactoid reaction: rash hypotension dyspnea wheezing GI disturbances: carbocisteine contraindicated for those with peptic ulcer.

Question 32

Who should you be more cautious of when prescribing mucolytics?

Answer 32

Elderly or debilitating patients with severe respiratory insufficiency asthma

Question 33

List an example of mucokinetics

Answer 33

Bromhexine with its active metabolite Ambroxol

Question 34

MOA of ambroxol:

Answer 34

it promotes mucus clearance: increase ciliary beat frequency, reduce adherence of mucus to cilia. stimulate surfactant production: an anti flu factor to prevent mucus from sticking to alveolar and bronchial walls antioxidant as free radical scavenger Anti inflammatory by decreasing cytokines Suppress influenza virus multiplication Local anaesthetic by blocking sodium channel.

Question 35

Side effects of ambroxol?

Answer 35

Allergic reactions cutaneous adverse effects avoid pts with hx of asthma and peptic ulcer disease caution <6 years old don't give those < 2 years old.

Question 36

is promethazine safe for geriatric use?

Answer 36

elderly more prone to sedation and confusion. anticholinergic effects can precipitate dementia. Contraindicated for narrow angle glaucoma

Question 37

is decongestant safe for geriatric use?

Answer 37

increased risk of htn and cardiovascular adverse events

Question 38

is codeine safe for geriatric use?

Answer 38

No, more susceptible for sedation and confusion

Question 39

is dextromethorphan safe for geriatric use?

Answer 39

No, more susceptible for sedation and confusion

Question 40

is Diphenhydramine safe for geriatric use?

Answer 40

elderly more prone to sedation and confusion. anticholinergic effects can precipitate dementia. Contraindicated for narrow angle glaucoma

Question 41

what is the best way to ensure recovery from a cough and a cold?

Answer 41

wait 3-7 days

Question 42

Agonists activate receptors. Antagonists block agonists from binding but on their own have no effect on receptor activity. What does antihistamine do on their own in the absence of histamine?

Answer 42

Produce the opposite effects to histamine