All of the following statements are TRUE about second generation antihistaminic agents EXCEPT:
These do not impair psychomotor performance
These possess high anti-motion sickness activity
These lack anticholinergic actions
These may possess additional antiallergic mechanisms
1st generation 2nd generation Cross BBB, cause sedation Donot cross BBB, no sedation Ach blockade, anticholinergic side effect occur No Ach blockade Useful for - Motion sickness - Drug induced parkinsonism - Muscular dystonias - Allergy Useful only for allergy Promethazine, diphenhydramine, diphenhydrinate, phenramine, Terfenadine, fexofenadine, loratidine
Histamine, 5-HT and PGs