H1 Antihistamines
Posted: 23rd July 2013 | Posted by AdminMR
H1 Antihistamines: Current Status and Future Directions
Simons, F. Estelle R.; Simons, Keith J.
World Allergy Organization Journal . 1(9):145-155, September 2008.
doi: 10.1097/WOX.0b013e318186fb3a
SUMMARY AND FUTURE DIRECTIONS
…Most of the second-generation H1 antihistamines currently in use have been identified by screening and structural modification of preexisting medications in the class. For example, cetirizine is a metabolite of hydroxyzine, levocetirizine is the active R-enantiomer of cetirizine, desloratadine is a metabolite of loratadine, and fexofenadine is a metabolite of terfenadine. New H1 antihistamines continue to be developed and introduced for clinical use51,52; however, such medications should be scrutinized closely because they may or may not represent important clinically relevant advances when compared with existing second-generation medications in the class. To date, no second-generation H1 antihistamine appears to have superior overall efficacy to the others, although some are safer than others.2-4…