<unk> -antihistamines are clinically used in the treatment of histamine-mediated allergic conditions. These indications may include: * Allergic rhinitis * Allergic conjunctivitis * Allergic dermatological conditions (contact dermatitis) * Rhinorrhea (runny nose) * Urticaria * Angioedema * Diarrhea * Pruritus (atopic dermatitis, insect bites) * Anaphylactic or anaphylactoid reactions—adjunct only * Nausea and vomiting * Sedation (first-generation<unk> -antihistamines)<unk> -antihistamines can be administered topically (through the skin, nose, or eyes) or systemically, based on the nature of the allergic condition. The authors of the American College of Chest Physicians Updates on Cough Guidelines (2006) recommend that, for cough associated with the common cold, first-generation antihistamine-decongestants are more effective than newer, non-sedating antihistamines. First-generation antihistamines include diphenhydramine (Benadryl), carbinoxamine (Clistin), clemastine (Tavist), chlorpheniramine (Chlor-Trimeton), and brompheniramine (Dimetane). However, a 1955 study of "antihistaminic drugs for colds," carried out by the U.S. Army Medical Corps, reported that "there was no significant difference in the proportion of cures reported by patients receiving oral antihistaminic drugs and those receiving oral placebos. Furthermore, essentially the same proportion of patients reported no benefit from either type of treatment."
H1 antagonist
GABA analogue
Muscarinic antagonist
Alpha-adrenergic agonist
Opioid antagonist
Beta-adrenergic agonist
5-HT3 antagonist
Beta2-adrenergic agonist