Antihistamines:Drugs that combat thehistaminereleased during anallergic reactionby blocking the action of the histamine on thetissue.Antihistaminesdo not stop the formation of histamine nor do they stop the conflict between theIgEandantigen. Therefore, antihistamines do not stop the allergic reaction but protect tissues from some of its effects. Antihistamines frequently causemouthdryness and sleepiness. Newer non-sedating antihistamines are generally thought to be somewhat less effective. Antihistamineside effectsthat very occasionally occur include尿液retentioninmales and fast heart rate.
