What are the general causes of rhinitis and rhinorrhoea?

Allergies, cold, chemical, or drug damage, cold air or physical damage.

 

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

A-agonists: Ephedrine

Antihistamines: Loratadine

Corticosteroids: Prednisone

Mast cell stabalisers: Ketotifen

Mucolytics: Mesna

Antibodies: Neomycin

 

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

Vasoconstriction of mucosal blood vessels, which decreases oedema of nasal mucosa. Topical decongestants have fewer side effects than drops becuse the drops end up in the GIT. The short acting drugs have a duration of 4-6 hours, the intermediary acting 8-10 hours and the long-acting have a duration of 12 hours.  There are mainly direct acting drugs, mixed action drugs (B-phenylephrine) and mixed action (Imidazole derivatives) .

 

What is rhinitis medicamentosa?  How is it treated?

Permanent vasoconstriction with poor local blood supply that leads to damage of mucosa membranes of the nose with permanent inflammation and swelling, and deregulation of the A-adrenergic receptors on the blood vessels, making them unresponsive to A-agonists.

 

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?

1st gen: clears up rhinorrhea, 2nd gen: treats allergic rhinitis, does not clear up cold rhinitis. 2nd generation does not cause sedation like the 1st gen. 2nd gen does not block muscarinic receptors.

 

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

corticosteroids are used for allergic rhinitis (topical, systemic)

anti-allergic drugs: effective for prophylactic treatment of allergic rhinitis (nasal spray- topical)

mensa: use when nasal secretion is sticky, makes mucus more liquid. (topical- nasal spray)

normal salt solution: nasal lavage