I am a 30 yr old female. I had cold some 9 months back but the coughing is still persisting till now. I had consulted a doctor, he told me that i am allergic to something and advised me to take cetrizine. I am daily taking that and if i skip any day, the coughing initates and it is so much that i vomit. It basically is more during night time and is continuous. Please advise me in this regard. Is it ok to take an antiallergic tablet daily?