All of the following statements are TRUE about second generation antihistaminic agents EXCEPT:
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
These do not impair psychomotor performance
These possess high anti-motion sickness activity
These lack anticholinergic actions
These may possess additional antiallergic mechanisms
Histamine, 5-HT and PGs