Cetirizine

Cetirizine is an antiallergic active substance belonging to the group of second-generation antihistamines.‍​‍‍‍​‍‍‍‍‍‍‍‍​‍ It is used for the treatment of hay fever, allergic rhinitis, allergic conjunctivitis, and urticaria. Compared with first-generation antihistamines, cetirizine causes less fatigue and drowsiness, as it barely crosses the blood-brain barrier. The onset of action is rapid and the effect is long-lasting, so that only one dose per day is required. Cetirizine (ATC R06AE07) has antihistaminic, antiallergic, and anti-inflammatory properties. It has high selectivity 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. However, both of these adverse effects may still occur. The onset of action is rapid and the effect is long-lasting. Mechanism of action of antihistamines, click to enlarge. Illustration © PharmaWiki