Agent nonsedating antihistamine bad things about internet dating
Antihistamines are inhibitors of histamine receptors. H1-antihistamines, inhibit competitively H1 receptors and the corresponding effects i. They do not inhibit antigen/antibodies reactions, nor histamine release, they inhibit H1 effects. H1-antihistamines have been used for more than fifty years in treating various allergic manifestations. H1-antihistamines which penetrate into brain elicit, by inhibiting stimulant effect of histamine, drowsiness.In addition to this antihistamine effect, they can have parallel pharmacological properties, for example antimuscarinic and adrenolytic effects which must be considered.It is usual to classify H1-antihistamines into two classes: old ones, called first-generation agents, which are sedating and recent ones, called second-generation agents which have slight or no sedating effects because they do not cross the blood-brain barrier.A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions. Any distribution or duplication of the information contained herein is strictly prohibited.
Other H1-antihistamines having an important antimuscarinic activity like diphenhydramine and dimenhydrinate, are used in preventive and curative treatment of motion sickness, but scopolamine which has no antihistamine effect seems more effective than them in preventive treatment.
The two first H1-antihistamines without sedating effect to be marketed were terfenadine and astemizole.
They were withdrawn from the market because they could induce ventricular arrhrythmias, prolongation of QT interval which can lead to torsades de pointes.
In case of overdose, loratadine can cause sedation and antimuscarinic effects.
Cetirizine, carboxyl derivative of hydroxyzine which is used as a sedative and anxiolytic, in addition to its H1-antihistamine effect, inhibits release of various cytokines and leukotrienes.