2024年12月12日 · Typically, antihistamines that treat H-2 receptor antagonists treat gastrointestinal symptoms. Both first-generation and minimally sedating antihistamines treat H-1 receptor...

2022年1月31日 · Sedative effect of antihistamines of the first generation is the result of their lipophilicity and the ability to penetrate the blood-brain barrier and bind to the H 1-histamine receptors of the brain. In addition, sedation can be caused by blocking the central serotonin and acetylcholine receptors.

Healthcare providers divide antihistamines into two major subtypes based on which histamine receptors they block: H1 receptors. H2 receptors. You have H1 receptors throughout your body, including in neurons (brain cells), smooth muscle cells of your airways and blood vessels.

2023年7月10日 · First-generation antihistamines easily cross the blood-brain barrier into the central nervous system and antagonize H-1 receptors, leading to a different therapeutic and adverse effect profile in contrast to second-generation antihistamines selectively bind to peripheral histamine receptors.

H1 receptor antagonists are typically utilized to suppress the body’s histamine-mediated effects in anaphylactoid or anaphylactic reactions. H2 antagonists are competitive antagonists at the parietal cell H2 receptor and are typically used to suppress gastric acid secretion.

First-generation antihistamines block both histaminic and muscarinic receptors as well as passing the blood-brain barrier. Second-generation antihistamines mainly block histaminic receptors but do not or only minimally cross the blood-brain barrier.

2024年7月17日 · Second-generation antihistamines focus on overcoming the main drawbacks of first-generation antihistamines, which are drowsiness and sedation. Because second-generation antihistamines are less likely to cross our blood-brain barrier, …

Historically, the combination of H1 and H2 receptor antagonists has been considered a classic treatment strategy, demonstrating relatively superior efficacy compared with single-drug therapies in the treatment of diverse histamine-mediated diseases.

H1 receptors and H2 receptors are both types of histamine receptors found in the body. H1 receptors are primarily located in smooth muscle cells, blood vessels, and nerve endings. When activated, H1 receptors mediate allergic reactions, such as itching, sneezing, and inflammation.

2008年4月7日 · In this review, we compare and contrast the clinical pharmacology, efficacy, and safety of first-generation H 1 antihistamines and second-generation H 1 antihistamines. First-generation H 1 antihistamines cross the blood-brain barrier, and in usual doses, they potentially cause sedation and impair cognitive function and psychomotor performance.