Best non sedating antihistamine
Since these effects are not genuine antagonistic but rather represent a balance displacement between active and inactive forms of H1 receptors, now, the term H1 antihistamine rather than the former “antihistamine antagonist” is used .
Bilastine is a new, well-tolerated, nonsedating H1 receptor antihistamine.Allergic symptoms occur when your body wrongly recognises a food or something (such as pollen spores) in your environment as a threat, and sends repair chemicals to deal to these perceived intruders.One of these repair chemicals, histamine, is released from repair cells called mast cells, which are scattered throughout the body.Bilastine has not been derived structurally from other antihistamines.It belongs to the piperidine class of antihistamines as do loratadine, desloratadine, and fexofenadine (Figure 1).Remember that cough or cold remedies often contain antihistamines, so if you are taking these as well you need to work out your total dosage to make sure you don’t take more than the total recommended amount for any one period.
Some people use antihistamines such as Phenergan and Vallergan as sedatives for their children, for example when they are travelling on a plane, but this can backfire as some children respond by becoming significantly more active (not a nice thing at 30,000 feet).
The effects of histamines are mediated through several receptors including H1, H2, H3, and H4 receptors that belong to the superfamily of G-protein-coupled receptors .
The biological effects of histamine in the allergic reaction are mediated through H1 receptors that coexist in active and inactive forms of g-protein-coupled receptors which balance each other.
Several mediators are involved in the pathophysiology; however, histamine plays a vital role in the allergic immediate reaction .
Once an allergen is introduced to Ig E-sensitized mast cells, a degranulation is triggered which causes histamine to be released.
Histamine works as an agonist that pushes the balance to the active side leading to effects such as muscular contraction, bronchospasms, upregulation of endothelial permeability, and stimulation of sensory nerves and cough receptors .