Tony Tse, a 33-year-old taxi driver, went to see his family doctor for his runny nose and clear nasal discharge. He said he has experienced these symptoms annually around spring time, adding that he has also suffered from irritated and itchy eyes. He reported no significant medical history and said he did not use other nonprescription or prescription medications. The doctor has now diagnosed him to have allergic rhinitis. He was prescribed combination therapy cetirizine-pseudoephedrine tablets to relieve his symptoms. 

(a) Regarding cetirizine:

(i) Name the class of drugs. (2 marks)

(ii) How does it work? (2 marks)

(iii) What are the advantages? (2 marks)

(b) Regarding pseudoephedrine:

(i) Name the class of drugs. (2 marks)

(ii) How does it work?  (2 marks)

(iii)What are the advantages? (2 marks)

(c) Later on, the family doctor realized that Tony suffered from childhood asthma before. Name the class of drugs with mechanism of action that are NOT recommended as a first line medication to treat allergic rhinitis, but may be helpful in those people who have both asthma and allergic rhinitis. State the route of administration. (4 marks)

(d) There is a common class of drugs which can be added in patients with severe allergic rhinitis symptoms affecting their quality of life. However, patients are sometimes hesitant to use it due to the fear of its adverse effects. Name this class of drugs with mechanism of action and address patients’ concern. (4 marks)