• What are the general causes of rhinitis and rhinorrhoea?

 Rhinitis and rhinorrhoea are caused by cold and flu, sinitus, allergen exposure (IgE mediated inflammation and physiological response due to stimuli (heat, smoke and cold weather).

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

Antihistamine e.g. diphenhydramine

corticosteroids e.g. mometasone

mucolytics e.g. mesna

alpha-1 agonists e.g. phenylephrine 

Anti-allergy drugs (sodium cromoglycate)

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

Decongestants MOA ( causes vasoconstriction of the mucosal blood vessels and decreases oedema of nasal mucosa)

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

intermediate acting drugs (8-10 hours), xylometazoline

long acting drugs (12 hours) oxymetazoline

They are administered  in the topical dosage form (nasal spray, drops and jellies) and inhalation of volatile compounds.

• What is rhinitis medicamentosa?  How is it treated?

Also known as rebound congestion or Privinism results from an overdose of local preparations. basically presents after chronic treatment with decongestants, where the permanent vasoconstriction with poor local blood supply leads to damage of the mucous membranes of the nose with inflammation and swelling.

Treatments: stop using the decongestants. gradually decrease your use of the medicine and for mild congestion use a saline nasal spray.

 

• 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 generation antihistamines are multipotent competing antagonist and blocks muscarinic receptors. Antimuscarinic drugs will reduce the secretions of both the upper and lower airways and are included in preparations for colds and clear up rhinnorhoea. 1st generation anti-histamines can cause sedation.

2nd generation anti-histamine do not block muscarinic receptors and are used in the long term or short term treatment of allergic rhinitis. these drugs do not help with the clear up of cold rhinitis, because histamine plays no part in cold rhinitis ( only bradykinin)

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

 corticosterioids- administered for allergic rhinitis, nasal sprays administered through nasal cavity.

anti-allergy drugs- allergic rhinitis and administered as a nasal spray

mesna- when nasal spray secretions is sticky and administered as a nasal spray.

normal salt solution- allergic rhinitis, mild congestion (nose drops)