Antihistamines, Decongestants, Antitussives, Expectorants & Mucolytic Flashcards
When cough is beneficial, do you need medicine ?
Do not medicate as the purpose is to clear foreign material from airway
When it is a productive cough, What medicine should be given ?
Expectorants
- Guaifenesin
Mucolytic
- Ambroxol
- Bromhexine
- Acetylcysteine (Cysteine derivatives)
- Carbocisteine (Cysteine derivatives)
Cysteine is an amino acid found naturally in the human body
When it is a non productive(dry) cough, What medicine should be given ?
Antitussives
Opioid
-Codeine
Non-Opioid
-Dextromethorphan
-Diphenhydramine
Is there is a nasal congestion due to allergic rhinitis. What medicine to use?
H1 Anti histamine
-1st Gen - Will sedate & dry mouth , cross into CNS,
Cholinergic antagonism: dry mouth, urinary retention, sinus tachycardia
α-adrenergic antagonism: hypotension, dizziness, reflex tachycardia
Serotonin receptor antagonism: increased appetite
-2nd and 3rd gen will not sedate
Intranasal Corticosteroids
- Fluticasone
What decongestants medication to use when nose block
Direct
- Phenylophrine (Alpha 1 Agonist)
- Oxymetazoline (dry mouth)
Indirect
- Ephedrine
- Pseudoephedrine
What happen during a common cold ?
- Viral infection of upper respiratory tract
- Resolve within 3-7 days
- Cough and cold medication for symptomatic
What is Antihistamines ?
inverse agonists
Name the first Generation antihistamine drug
Chlorpheniramine
Diphenhydramine
Promethazine
Name the first Generation antihistamine drug use to treat motion sickness
Diphenhydramine
Dimenhydrinate
Cyclizine
How do H1 antihistamines work?
-Physically blocking the H1 receptors so histamine from reaching its target. decreases your body’s reaction to allergens
First generation Anti histamine also interact with ______?
- Beside H1 , it also interact with muscarinic cholinergic, alpha-adrenergic and serotonin receptors
Second generation Anti histamine also interact with ______?
Reduced lipophilicity or greater p-glycoprotein efflux pump
affinity and so reduced CNS effects
Name all the 2nd Generation ANti histamine drug
Centrizine - Abit sedation
Fexofenadine
Loratadine
Name all the 3rd Generation ANti histamine drug
Levocetrizine
Desloratadine
What is the effective duration for 1st generation vs 2nd generation Anti histamine drug ?
1st Gen - 4-6H
2nd Gen - 12-24H
Which human organ is use to metabolise the 1st generation vs 2nd generation Anti histamine drug ?
1st Generation - Liver
2nd Generation - Liver P450 with active metabolites
Discuss how 1st generation vs 2nd generation Anti histamine drug is excreted ?
1st Generation - Urine
2nd Generation - Urine , Feces
Name all the Decongestants drugs use to clear congestion (Oral)
Oral / Intranasal
- Phenylephrine
- Pseudoephedrine
- ephedrine
- Oxymetazoline
Mechanism of action
- “Peseu & ephedrine”increase adrenaline
- “Phen & Oxy “ work on Alpha 1 adrenoceptor agonist
• Vasoconstriction of nasal blood vessels
• Reduce inflammation and secretion of mucus
Name the adverse effect of Sympathomimetic Agents that help in decongestion
• Rebound congestion
• Occurs with prolonged (> few days) use of topical intranasal
decongestants
• CNS stimulation
• More likely with oral decongestants
• Restlessness, tremors, irritability, anxiety and insomnia
• Cardiovascular
• More likely with oral decongestants
• Hypertension due to vasoconstriction
• Palpitations (indirect sympathomimetics e.g. pseudoephedrine)
Name all the Decongestants drugs use to clear congestion (Intranasal)
Intranasal
Fluticasone - Nasal Glucocorticoid
Mechanism of Action:
• Anti-inflammatory
Name all the Glucocorticoids Decongestants adverse effect.
- Systemic side effects limited by intranasal delivery
- Local mucosal dryness and irritation
Name a few Antihistamine-Decongestant Combinations
Chlopheniramine + Pseudephedrine
Diphenhydramine + Pseudephedrine
Name the advantage and disadvantage og Opioid Antitussives
Name the advantage and disadvantage of NON-Opioid Antitussives
Names the action mechanism and adverse effect?
Mechanism of Action: Acts in CNS to suppress cough
- CNS – sedation
- Weak opioid but still has abuse potential at high dose
- Respiratory depression
• Should not occur at normal clinical doses
• Risk on overdose
• Risk in patients with severe respiratory insufficiency - Do not combine with other CNS depressants
What is the recommended does of codeine for adult and children ?
Adult - 10 to 20 mg every 4 to 6 times a day
Children not recommended as liver and respiratory centre are not developed
Name the working mechanism and adverse effect of Non Opioid Antitussives - Dextromethorphan
Mechanism of Action: • Acts in CNS to suppress cough
Adverse Effects:
• CNS – drowsiness, dizziness
• Gastrointestinal – nausea, vomiting, stomach pain
• Abuse potential at high dose (dissociative anaesthetic-like effect)
Name the working mechanism and adverse effect of Non Opioid Antitussives - Diphenhydramine
Mechanism of Action:
• Antihistamine; Mechanism of antitussive action unknown
Adverse Effects:
• Sedative, anticholinergic
Name Guaifenesin (expectorants) mechanism of action and adverse effects It is a component in many cough mixture formulations
Mechanism of action:
• Increases production of respiratory tract fluids to help liquefy and
reduce viscosity of tenacious secretions
Adverse Effects:
• Gastrointestinal disturbance, nausea
Cannot use for patient with persistence cough associated with asthma and smoking . Take more fluid
Name the Mucolytics mechanism of action and adverse effect
Mechanism of action:
• Free sulfhydryl group opens disulphide bonds in mucoproteins
• Lowers mucous viscosity
Adverse Effects:
• Bronchospasm
• Anaphylactoid reactions – rash, hypotension, dyspnea, wheezing
• Gastrointestinal disturbance
Caution :
• Cannot use for Elderly or debilitated patients with severe respiratory insufficiency
• Patients with asthma
List all Mucolytics drug
Acetylcysteine,
carbocisteine,
ambroxol,
bromhexine
Can cought and cold medicine use for children? (e.g. Promethazine, Antihistamine, cough suppressants, cold and flu product)
Below 6 month - Not recommended for all
6mth- 2years old - Promethazine cannot use while all other use if benefits outweight risk
2 years above - Use with cayion for all
Is cough and cold medication suotable for elderly use
