• What are the general causes of rhinitis and rhinorrhoea?

General causes of rhinitis and rhinorrhoea are allergens, cold chemical or drug damage, cold air and physical damage

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

Mucolytics – acetylcysteine, mensa

Alpha1 agonists – ephedrine

Corticosteroids – prednisone, betamethasone

Antihistamine – rupatadine

Diverse drugs – steam, normal saline

Antibiotics – neomycin

Mast cell stabilizers - ketotifen

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

We have:

short-acting drugs (4-6 hours) ephedrine, phenylephrine

intermediate acting drugs (8-10 hours), xylometazoline

long acting drugs (12 hours) oxymetazoline

• What is rhinitis medicamentosa?  How is it treated?

A condition that is caused by overusing nasal decongestants and it is firstly treated by the cessation of nasal decongestants or using a saline nasal spray or corticosteroids nasal spray in topical form

• 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 drugs block muscarinic and histaminic receptors leading to increased vasoconstriction leading to mucus thickening however, it will have anti-inflammatory effects  but also have sedation effects. While 2^nd generation drugs block only histaminic receptors having anti-inflammatory effects and anti-allergic effects and the can be used long term without side effects. Histamine has no effects on cold rhinitis

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

normal saline solution is highly recommended in the treatment of children, corticosteroids are administered in the treatment of rhinitis medicamentosa and the are recommended in allergic rhinitis and all these are administered through topical nasal spray