What are cetirizine / antihistamines?

This video tells us about cetirizine and its antihistamine action. its chemical structure, classification, dosage strength, side effects and its mechanism of action. TIMELINE: 0:04 Introduction 0:11 Chemical structure 0:19 Pharmacological classification 0:46 Mechanism of drug action 1:00 Indications 1:12 Dosage form and strength 1:23 Side effects of drug usage 1:35 Patient counselling 2:00 Conclusion