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

The general causes of rhinitis and rhinorrhoea are usually allergies, cold, chemical or drug damage, cold air or physical change.

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

The alpha-1 antagonists, examples include phenylephrine, ephedrine, naphazoline etc.

Antimuscarinic and antihistaminic drugs, first generation histamine include brompheniramine, second generations histamine include loratadine.

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

Decongestants produce their action by activating the postjunctional alpha-adrenergic receptors found on precapillary and postcapillary blood vessels of the nasal mucosa, with regards to their duration of action, they usually start working within 15-30 minutes and will last anywhere from 3-12 hours. They are typically administered as a pill or as nose drops, sprays or gels.

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

Rhinitis medicamentosa is a condition that develops 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 permanent inflammation and swelling, as well as deregulation of the alpha-adrenergic receptors on the blood vessels making them unresponsive towards the alpha-agonists. Treatment involves gradually decreasing the use of nasal sprays, if congestion is mild a saline spray is recommended.

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

These drugs are valid in allergic rhinitis and they are administered as nasal sprays.