Histamine structure. Image source: Wikipedia.
The study authors compared the effects of 3 modem nsAHs with those of the fgAH hydroxyzine on histamine- and allergen-induced skin reactions in a double-blind trial.
The nsAHs prevented the development of positive reactions to histamine in only 10-20% of all individuals tested. In contrast, more than 50% of all hydroxyzine-treated individuals showed negative test reactions to histamine. Similar differences, although less pronounced, were detected with D pteronyssinus prick (dust mite) testing in sensitized individuals.
The authors concluded that hydroxyzine is more effective than nsAHs in suppressing histamine-induced or allergic skin reactions.
Higher doses of nsAHs than those currently recommended may be required to obtain antihistaminic and antiallergic effects that are equivalent to those of fgAHs.
Oral Antihistamines (mind map)
Suppression of histamine- and allergen-induced skin reactions: comparison of first- and second-generation antihistamines. dos Santos RV, Magerl M, Mlynek A, Lima HC. Ann Allergy Asthma Immunol. 2009 Jun;102(6):495-9.
Patient response to different antihistamines will vary http://goo.gl/Q2PiV