STUDY UNIT 3.4

1. What are the general causes of rhinitis and rhinorrhoea?

• Allergies
• Cold
• Chemical or drug damage
• Cold air
• Physical damage

2. Which drug groups can be used for the treatment of rhinorrhoea? Name examples from each group.

• α1- agonists: Phenylephrine

• Antihistamines: Promethazine
• Corticosteroids: Betamethasone
• Mast cell stabilizers: Sodium chromoglycate
• Mucolytics: Acetylcysteine
• Antibiotics: Mupirocin
• Diverse drugs: Normal saline

3. How do the decongestants differ with respect to the mechanism of action and duration of action?  How are they administered typically?

MOA: They present α -adrenoceptor sympathomimetics and therefore cause vasoconstriction this will reduce nasal airway resistance and allow breathing through the nose.

Duration of action:

• Short-acting drugs (4 to 6 hours), e.g. ephedrine, phenylephrine, propylhexedrine, naphazoline and tetrahydrozoline;

• Intermediary acting drugs (8 to 10 hours), e.g. xylometazoline;

• Long-acting drugs (12 hours), e.g. oxymetazoline.

Should however only be used for 5-7 days

They administered topically as it is the safest

4. What is rhinitis medicamentosa?  How is it treated?

It is the drying out of the nasal mucosal tissue which will lead to a blocked nose. It is treated with a topical cortisone in the form of a nasal spray e.g., beclomethasone

5. How does the first and second generations of antihistamines differ with respect to the mechanisms according to which rhinitis and rhinorrhoea are relieved?  What are the advantages of the second generation of antihistamines?  Why should they not be used to relieve cold rhinitis?

1^st generation antihistamines are multipotent competing antagonists which block muscarinic receptors. These muscarinic antagonists reduce the secretions of the upper and lower airways. They will therefore be used in the preparations for colds which will clear up rhinorrhoea.

2^nd generation antihistamines do not block muscarinic receptors and are used in both long- and short-term treatment for allergic rhinitis.

6. When are corticosteroids, anti-allergic drugs, mesna and normal salt solution valid and how are they administered?

• Corticosteroids: Allergic rhinitis, administration is topical,
• Anti-allergic drugs: Prophylactic treatment of allergic rhinitis; nasal spray
• Mensa: Makes mucus a liquid; nasal spray.
• Normal salt solution: Nasal lavage.

STUDY UNIT 3.4

1. What are the general causes of rhinitis and rhinorrhoea?

• Allergies
• Cold
• Chemical or drug damage
• Cold air
• Physical damage

2. Which drug groups can be used for the treatment of rhinorrhoea? Name examples from each group.

• α1- agonists: Phenylephrine

• Antihistamines: Promethazine
• Corticosteroids: Betamethasone
• Mast cell stabilizers: Sodium chromoglycate
• Mucolytics: Acetylcysteine
• Antibiotics: Mupirocin
• Diverse drugs: Normal saline

3. How do the decongestants differ with respect to the mechanism of action and duration of action?  How are they administered typically?

MOA: They present α -adrenoceptor sympathomimetics and therefore cause vasoconstriction this will reduce nasal airway resistance and allow breathing through the nose.

Duration of action:

• Short-acting drugs (4 to 6 hours), e.g. ephedrine, phenylephrine, propylhexedrine, naphazoline and tetrahydrozoline;

• Intermediary acting drugs (8 to 10 hours), e.g. xylometazoline;

• Long-acting drugs (12 hours), e.g. oxymetazoline.

Should however only be used for 5-7 days

They administered topically as it is the safest

4. What is rhinitis medicamentosa?  How is it treated?

It is the drying out of the nasal mucosal tissue which will lead to a blocked nose. It is treated with a topical cortisone in the form of a nasal spray e.g., beclomethasone

5. How does the first and second generations of antihistamines differ with respect to the mechanisms according to which rhinitis and rhinorrhoea are relieved?  What are the advantages of the second generation of antihistamines?  Why should they not be used to relieve cold rhinitis?

1^st generation antihistamines are multipotent competing antagonists which block muscarinic receptors. These muscarinic antagonists reduce the secretions of the upper and lower airways. They will therefore be used in the preparations for colds which will clear up rhinorrhoea.

2^nd generation antihistamines do not block muscarinic receptors and are used in both long- and short-term treatment for allergic rhinitis.

6. When are corticosteroids, anti-allergic drugs, mesna and normal salt solution valid and how are they administered?

• Corticosteroids: Allergic rhinitis, administration is topical,
• Anti-allergic drugs: Prophylactic treatment of allergic rhinitis; nasal spray
• Mensa: Makes mucus a liquid; nasal spray.
• Normal salt solution: Nasal lavage.