What are the common causes of rhinitis and rhinorrhea?
These conditions are usually the result of allergies, colds, chemical or drug damage, cold air or physical damage

 What drug groups can be used in the treatment of rhinorrhea? Give examples to each group.
Anti-infective: Mupirosin, Neomasin
α1 agonists (decongestants): phenylephrine, ephedrine, oxymetazoline
Antihistamines: Diphenhydramines, Promethazine, Loratadiene
Corticosteroids: Betamethasone, Prednisone, Budesonide
Antiallergic drugs: Sodium chromoglycate, Nedochromyl sodium
Mucolytics: Mesna, acetylcysteine

Miscellaneous: Steam, saline, essential oils, menthol

 How do the decongestants differ from each other in terms of mechanism of action and duration of action? 
How are they typically administered?

MVW: decongestants are α1 agonists and therefore cause vasoconstriction of mucosal blood vessels and 
decreased edema of nasal mucosa
Operating time: it takes about 4hrs. however, it should not be used for more than 3 days in a row and
 should not be drunk after 16:00.

 What isrhinitis medicamentosa? How is it treated?
It is very severe nasal congestion caused by overuse of decongestant nasal sprays or drops.
It is treated with corticosteroid nasal sprays

 How do the first and second generation antihistamines differ in the mechanisms of action by 
which rhinitis and rhinorrhea are relieved? What are the benefits of second generation antihistamines? 
Why should they not be used to relieve cold sores?

Antihistamines are rarely used due to mucus thickening.

1st generation:
It is effective but causes sedation and decreased concentration
2nd generation:
Effective in allergic rhinitis.
Advantages: can be used in the long run.
It should not be used in cold rhinitis as 2nd generation antihistamines are effective in allergic rhinitis
 and colds are therefore not an allergic reaction.

When are corticosteroids, anti-allergic drugs, mesna and normal saline useful 
and how are they administered?
 Corticosteroids:
is used in reversal of rhinitis medicamentosa
Administered by nasal spray

Antiallergic drugs:
is used for allergic rhinitis
is applied by means of a nasal spray

Mesna:
Used in the treatment of sticky nasal mucus

Normal saline solution:
To dilute mucus in sinusitis.
Rinse with salt dissolved in water 2-4 times a day