
The antihistamines are given in tablet form. They're used for all sorts of allergies, hayfever, etc. An allergy is the body's immune system over-reacting to a stimulus, i.e pollen, washing powder, etc, and I think that the reaction is triggered or caused by something in the body called histamine, so anti histamines suppress the action of these.
Anyway, the simple action is that they stop allergic reactions of all kinds! :D
Paula