Allegra Nasal Duo Spray is a combination medicine used in the treatment of allergy symptoms such as runny nose, stuffy nose, sneezing, watery eyes and congestion or stuffiness. Allegra Nasal Duo Spray should be used as you have been advised by your doctor. Do not use it more often or for longer than recommended. Normally you should blow your nose gently before using it. Keep one nostril closed while instilling the medicine into the other, and then sniff hard to make sure it reaches deep into the nose. Then repeat for the other nostril. It provides relief very quickly and can last for several hours. The most common side effects are taste change, nosebleeds, and headaches. Most of these are temporary and usually resolve with time. Contact your doctor straight away if you are at all concerned about any of these side effects. Never support self-medication or recommend your medicine to another person. It is beneficial to have plenty of fluids while taking this medication. Before you start taking this medicine it is important to inform your doctor if you are suffering from liver or kidney disease. You should also tell your doctor if you are pregnant, planning pregnancy, or breastfeeding.