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. 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.
This selectivity significantly reduces the occurrence of adverse drug reactions, such as sedation, while still providing effective relief of allergic conditions.
E-triprolidine, for example, is 1000-fold more potent than Z-triprolidine.
This difference relates to the positioning and fit of the molecules in the histamine HThese compounds are structurally related to the ethylenediamines and the ethanolamines, and produce significant anticholinergic adverse effects.
receptor, helping to relieve from allergic reactions.
Agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines; other agents may have antihistaminergic action but are not true antihistamines.
Many people have demanding lives and cannot be sneezing and feeling groggy all day.