Bamirastine

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Bamirastine is a second-generation antihistamine that is used primarily for the treatment of allergic rhinitis and urticaria. It is known for its selective antagonism of the histamine H1 receptor, which helps alleviate symptoms associated with allergic reactions such as sneezing, itching, and hives.

Pharmacology

Bamirastine functions by competitively inhibiting the binding of histamine to the H1 receptor. This action prevents the cascade of events that lead to the symptoms of allergic reactions. Unlike first-generation antihistamines, bamirastine is less likely to cross the blood-brain barrier, which reduces its sedative effects.

Mechanism of Action

The primary mechanism of action of bamirastine involves blocking the H1 receptor, which is a G-protein coupled receptor located on the surface of various cells, including those in the respiratory tract, skin, and vasculature. By preventing histamine from binding to these receptors, bamirastine reduces the vasodilation, increased vascular permeability, and sensory nerve stimulation that contribute to allergic symptoms.

Pharmacokinetics

Bamirastine is well absorbed after oral administration, with peak plasma concentrations typically occurring within 1 to 3 hours. It is metabolized in the liver and excreted primarily in the urine. The half-life of bamirastine is approximately 8 to 12 hours, allowing for once or twice daily dosing.

Clinical Use

Bamirastine is indicated for the relief of symptoms associated with seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria. It is effective in reducing symptoms such as nasal congestion, sneezing, itching, and hives.

Side Effects

Common side effects of bamirastine include headache, dry mouth, and fatigue. Due to its reduced penetration of the blood-brain barrier, it is less likely to cause drowsiness compared to first-generation antihistamines.

Contraindications

Bamirastine should be used with caution in patients with severe hepatic impairment, as its metabolism may be affected. It is also contraindicated in patients with known hypersensitivity to bamirastine or any of its components.

Research and Development

Bamirastine was developed as part of efforts to create antihistamines with fewer central nervous system side effects. Ongoing research is focused on its efficacy in various allergic conditions and its potential use in combination therapies.

Also see

• Antihistamine
• Allergic rhinitis
• Urticaria
• Histamine H1 receptor

First Generation Antihistamines

• Brompheniramine
• Carbinoxamine
• Chlorcyclizine
• Chlorpheniramine
• Clemastine
• Cyclizine
• Cyproheptadine
• Dexbrompheniramine
• Dexchlorpheniramine
• Dimenhydrinate
• Diphenhydramine
• Doxylamine
• Hydroxyzine
• Meclizine
• Phenyltoloxamine
• Promethazine
• Triprolidine

Second Generation Antihistamines

• Acrivastine
• Cetirizine
• Fexofenadine
• Levocetirizine
• Loratadine
• Desloratadine