ZyrCold Syrup 100 ml, are generally used to treat coughs. An allergic reaction is an immune system reaction to outside substances that are usually not detrimental to your body. These alien substances are referred to as "allergens." The severity of allergies varies from person to person. Some people may have dietary allergies as well as seasonal allergies like hay fever. Others can have allergies to pet dander or pollen. Coughing is one of the signs of allergies. When mucus or any other external irritant gets in the throat, a reflexive coughing motion takes place. Cetirizine is a member of the antihistamine or anti-allergic drug subclass. It prevents the 'histamine' chemical messenger from doing its job.Disclaimer:For more information contact your physician.