Zepastine

An antihistamine used in the treatment of allergic conditions

Zepastine is a second-generation antihistamine used primarily in 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 runny nose.

Pharmacology

Zepastine works by blocking the action of histamine, a substance in the body that causes allergic symptoms. As a second-generation antihistamine, it is less likely to cause drowsiness compared to first-generation antihistamines. This is due to its reduced ability to cross the blood-brain barrier.

Mechanism of Action

Zepastine selectively binds to the H1 receptor, preventing histamine from exerting its effects on these receptors. This action reduces the symptoms of allergic reactions, such as vasodilation, increased vascular permeability, and sensory nerve stimulation.

Pharmacokinetics

Zepastine is well absorbed after oral administration, with a high bioavailability. It is extensively metabolized in the liver and has a half-life of approximately 8 to 10 hours, allowing for once or twice daily dosing. The drug is primarily excreted via the kidneys.

Clinical Use

Zepastine is indicated for the relief of symptoms associated with:

• Allergic rhinitis: Including seasonal and perennial forms, characterized by symptoms such as nasal congestion, sneezing, and itching.
• Urticaria: Also known as hives, which are characterized by itchy, raised welts on the skin.

Side Effects

Common side effects of Zepastine include:

• Headache
• Dry mouth
• Fatigue

Less common side effects may include:

• Drowsiness
• Nausea
• Dizziness

Contraindications

Zepastine is contraindicated in patients with known hypersensitivity to the drug or any of its components. Caution is advised in patients with severe renal impairment due to the drug's primary route of excretion.

Interactions

Zepastine may interact with other central nervous system depressants, enhancing their sedative effects. It is also advised to avoid alcohol consumption while taking this medication.

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