Duozinal

Cetirizine is an antiallergic agent belonging to the second-generation antihistamines. It is used to treat hay fever, allergic rhinitis, allergic conjunctivitis, and urticaria. Compared with first-generation antihistamines, cetirizine causes less fatigue and drowsiness because it barely penetrates the brain. Its onset of action is rapid and the effect is long-lasting, so once-daily dosing is sufficient. Cetirizine (ATC R06AE07) has antihistaminic, antiallergic, and anti-inflammatory properties. It is highly selective for the H1 receptor and is neither anticholinergic nor cardiotoxic. Cetirizine crosses the blood-brain barrier only to a negligible extent and therefore causes less fatigue and drowsiness than first-generation antihistamines. Nevertheless, both adverse effects may still occur. The onset of action is rapid and the effect is sustained. Mechanism of action of antihistamines — click to enlarge. Illustration © PharmaWiki