High blood pressure. Causes, symptoms, treatments

Arginine vasopressin enhances sympathetic constriction through the V1 vasopressin receptor in human saphenous vein.


To describe the therapeutic approach in patients with CU, and to depict how recent guidelines are implemented in the daily practice of management of CU.

These findings suggest that treatment with desloratadine has considerable beneficial effects on work place performance when individuals suffer from SAR.

Here, we show that oral treatment with first-generation H1R antihistamine diphenhydramine, H2R blocker cimetidine and H3/4R blocker thioperamide impairs optimal innate immune responses in severe murine bacterial sepsis. However, these adverse effects are not mediated by H1R, as mice deficient for H1R show similar rates of morbidity and mortality after CLP as their wild-type controls. Similarly, the second-generation antihistamine desloratadine neither affects morbidity nor mortality after CLP.

The current study revealed that during the 5-day treatment with recommended doses of cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine, a significant reduction of histamine-induced wheal, flare and the LDF index was observed as compared to the initial values and placebo intake, reaching the maximum value within the first 24 hours, weakening on the next day, and then gradually increasing during the following days. After the 5-day treatment drugs used for the study were lined up according to the volume of reduction in histamine-induced skin reaction (largest>smallest): levocetirizine > cetirizine > fexofenadine 180mg = fexofenadine 120mg > loratadine = desloratadine.

We evaluated changes in the binding properties of sedative and non-sedative histamine H1-receptor antagonists induced by internalization of H1 receptors in intact human U373 MG astrocytoma cells. Internalization of H1 receptors was induced without their degradation by treatment with 0.1 mM histamine for 30 min at 37 degrees C, and then the intact cell binding assay was performed at 4 degrees C. The binding properties of [3H]mepyramine, a cell-penetrating radioligand for H1 receptors, were not changed by histamine pretreatment. Displacement curves for sedative H1-receptor antagonists (diphenhydramine, chlorpheniramine, promethazine, ketotifen, azelastine and oxatomide) against [3H]mepyramine binding were not changed by histamine pretreatment. In contrast, the displacement curves for non-sedative H1-receptor antagonists (mequitazine, bepotastine, olopatadine, epinastine, carebastine, desloratadine and fexofenadine) were changed by histamine pretreatment: two types of changes, i.e. a rightward shift in the monophasic curve or an increase in the proportion of the low affinity component of the biphasic curve, were prevented under hypertonic conditions, in which clathrin-mediated receptor internalization is known to be inhibited. Thus, internalization-mediated changes in the binding properties of H1-receptor antagonists were well correlated with their sedative and non-sedative behaviors, which might confirm their permeability through the biomembrane and possibly the blood brain barrier.

The review of these data indicates that the safety profile of desloratadine is similar to other second-generation antihistamines. Desloratadine is highly selective for histamine H₁-receptors, does not cross the blood-brain barrier (BBB), and has minimal adverse events (very low sedation rate), with a better safety and tolerability than first-generation antihistamines. Desloratadine is safe and well tolerated without having central nervous system (CNS) or cardiovascular effects and with low drug interaction.

A MEDLINE search (1966-2002) was performed to obtain studies examining the use of antihistamines in the treatment of atopic dermatitis. Search terms included: atopic dermatitis; eczema; antihistamines; azatadine; brompheniramine; cetirizine; chlorpheniramine; clemastine; cyclizine; cyproheptadine; desloratadine; diphenhydramine; fexofenadine; hydroxyzine; loratadine; meclizine; promethazine; trimeprazine. Further references were gathered from these publications.

The majority of patients were from urban areas (82%). The most common allergic diseases in the study group were: urticaria (21%), allergic rhinoconjunctivitis (14%), allergic bronchitis (14%) and allergic asthma (12%).

After 1 and 2 weeks of treatment, symptoms scores were significantly decreased in the A group and C group compared with the placebo group (P < 0.05). After 1 and 2 weeks of treatment by the methods of A and C, the QOL of patients with seasonal allergic rhinitis was significantly improved compared with placebo group (P < 0.05). There was no QOL improvement in the placebo group.

In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.

To prove methotrexate's efficiency in patients with autoimmune urticaria.