Non sedating second and third generation antihistamines Sister cam
For this reason, some second-generation antihistamines are available as combination preparations containing a decongestant.They are often preferred for first-line therapy of allergic rhinitis, especially for seasonal or episodic symptoms, because of their excellent efficacy and safety profile. The second-generation oral antihistamines currently available in the United States are cetirizine, levocetirizine, desloratadine, fexofenadine, and loratadine.Competes with histamine for H1 receptors in GI tract, blood vessels, and respiratory tract, reducing hypersensitivity reactions. Bedtime dosing may be useful if sedation is a problem. Second-generation agent with a rate of sedation not significantly different from that of placebo.
Ocular antihistamine drops (for eye symptoms), intranasal antihistamine sprays, intranasal cromolyn, intranasal anticholinergic sprays, and short courses of oral corticosteroids (reserved for severe, acute episodes only) may also provide relief.
Competes with histamine on H1-receptor sites on effector cells in blood vessels and respiratory tract.
For symptomatic relief of symptoms caused by release of histamine in allergic reactions. May suppress histamine activity in subcortical region of CNS.
Most cases of allergic rhinitis respond to pharmacotherapy.
Patients with intermittent symptoms are often treated adequately with oral antihistamines, decongestants, or both as needed.
When used as a single agent, has been shown to result in a reduction of seasonal allergic rhinitis symptoms, similar in degree to that of loratadine.