Resp - Cough and Cold Medicines Flashcards
List the classes of drugs used for rhinorrhoea (runny nose/sneezing) and nasal congestion (blocked nose)
(1) Mucoregulator - intranasal ipratropium
(2) Mast cell stabiliser - intranasal/inhaled cromoglicic acid
(3) H1 antihistamines
(4) Decongestants:
(A) intranasal corticosteroid
(B) sympathomimetic decongestants
List the classes of drugs used for sore throat, headache and fever associated with common cold.
(1) Analgesics e.g., NSAIDs or paracetamol
(2) Antipyretics e.g., NSAIDs or paracetamol
List the classes of drugs used for cough.
(1) For “dry”/non-productive cough: Antitussives (cough suppressants)
(2) For “wet”/productive cough:
(A) Expectorants
(B) Mucoactive agents:
(i) Mucolytics
(ii) Mucokinetics
What is post-nasal drip?
Post-nasal drip is when mucus drips down from the back of the inflamed nasal cavity into the nasopharynx and hence the throat.
Post-nasal drip can cause cough. Cough caused by post-nasal drip can be alleviated by the classes of drugs used to treat rhinorrhoea (mucoregulators, mast cell stabilisers, antihistamines, and decongestants).
For the treatment of rhinorrhoea associated with common cold, which classes of drugs have the greatest evidence of clinical efficacy?
Evidence-based medicine suggests that (1) analgesics (2) mucoregulators (e.g., intranasal ipratropium), and (3) mast cell stabilisers (e.g., cromoglicic acid) may be effective.
Likewise, there is evidence that antihistamines and decongestants combined may be effective, but the evidence for the efficacy of antihistamines or decongestants alone is minimal or uncertain.
(UpToDate Sep 2021 “The common cold in adults: Treatment and prevention”)
Name an example of a mucoregulator used to treat symptoms of common cold. Briefly, explain its route of administration and mechanisms of action.
Ipratropium bromide
- Delivered intranasally
- Short-acting muscarinic receptor antagonist (SAMA)
- Blocks inflammation‐induced parasympathetic cholinergic receptor (M3) activation of submucosal glands/goblet cells
Importantly, does not dry basal secretion and does not increase the normal viscosity of mucus.
List common adverse effects of ipratropium when administered intranasally
- Few side effects as little enters systemic circulation via intranasal route
- Unpleasant taste
- Dry mouth
- Urinary retention (elderly particularly susceptible)
Name a mast cell stabiliser that can be used to control symptoms of common cold. Briefly explain the route of administration and the mechanisms of action.
Cromoglicic acid
- Intranasal or inhaled
- Controls chloride (Cl-) channels to inhibit cellular activation
- ↓mast cell degranulation induced by IgE-mediated FcεRI crosslinking
- ↓ secretion of inflammatory mediators from eosinophils, neutrophils and macrophages
- ↑ secretion of annexin A1
- AnnexinA1 inhibits prostaglandin and leukotriene production
List common side effects of cromoglicic acid
- Throat and nasal irritation, mouth dryness, cough
- Unpleasant/Bitter taste
List FIVE examples of sympathomimetic decongestants.
- Phenylephrine (direct alpha-1 agonist)
- Oxymetazoline (nonselective direct alpha agonist)
- Naphazoline (nonselective direct alpha agonist)
- Pseudoephedrine (indirect sympathomimetic)
- Ephedrine (indirect sympathomimetic)
List typical routes of administration of common sympathomimetic decongestants
- Direct alpha adrenoceptor agonists
- Alpha-1 selective: Phenylephrine (oral or intranasal)
- Non-selective: Oxymetazoline (intranasal) / naphazoline (intranasal)
- Indirect increase in release of adrenaline/noradrenaline
- Pseudoephedrine (oral) / Ephedrine (intranasal)
Name TWO examples of corticosteroids administered intranasally as decongestants
- Fluticasone
- Mometasone
Intranasal administration of corticosteroids reduces the risk of systemic adverse effects. What is the MOST LIKELY adverse effect of intranasal corticosteroids?
Local mucosal dryness and irritation
Intranasal administration of corticosteroids reduces the risk of systemic adverse effects.
What is an adverse effect specific to intranasal fluticasone that can affect compliance in some patients?
Some people report that intranasal fluticasone has a “rose water” odour that they cannot tolerate
List common adverse effects of sympathomimetic decongestants.
- Rebound congestion
- Occurs with prolonged (> few days) topical intranasal use
- CNS stimulation
- More likely with oral decongestants (e.g., pseudoephedrine or phenylephrine)
- Restlessness, tremors, irritability, anxiety and insomnia
- Cardiovascular
- More likely with oral decongestants (e.g., pseudoephedrine or phenylephrine)
- Hypertension due to vasoconstriction
- Tachycardia (indirect sympathomimetics e.g., pseudoephedrine)
- Dry mouth
- Alpha-2 agonist effect on salivary gland (e.g., oxymetazoline or pseudoephedrine but not phenylephrine)
List THREE antitussive drugs
- Opioid antitussives
- Codeine
- Nonopioid antitussives
- Dextromethorphan
- Diphenhydramine
List advantages and disadvantages of codeine as an antitussive
Advantages:
- Most effective antitussive
Disadvantages (greater for CYP2D6 ultra-rapid metabolisers who convert more codeine to morphine faster):
- Potential for abuse
- Sedation
- Respiratory depression on overdose
List advantages and disadvantages of dextromethorphan as an antitussive
Advantages:
- Less risk of addiction
- Most effective non-opioid antitussive
Disadvantages:
- Drowsiness, dizziness (although less than codeine)
- Gastrointestinal adverse effects
- Potential for abuse at high doses
List advantages and disadvantages of diphenhydramine as an antitussive
Advantages
- No risk of addiction
Disadvantages
- Sedation
- Anticholinergic adverse effects
Below what age is codeine not recommended as an antitussive?
Codeine is not recommended as antitussive < 18 years old.
Below what age is dextromethorphan not recommended as an antitussive?
Not recommended < 4 years old
Below what age is guaifenesin not recommended?
Caution < 6 years old
Not indicated < 2 years old
Below what age are sympathomimetic decongestants contraindicated?
Below 12 years old
What is the MOST IMPORTANT advice for a patient prescribed guaifenesin?
Take adequate fluid to make secretions less viscous and
protect renal function (nephrolithiasis reported on overdose)
To what class of drugs does guaifenesin belong?
Expectorants
Name TWO examples of mucolytics
Acetylcysteine, carbocisteine
Name TWO examples of mucokinetics
Bromhexine and its active metabolite ambroxol
