<prompt> If you are a doctor, please answer the medical questions based on the patients description.MY DAUGHTER HAVING COUGH FOR 3 WEEKS NOW,THE FIRST WEEK I BROUGHT HER IN AN DOCTOR AND THE DOCTOR GAVE HER ANTIBIOTIC.SHE FINISHED TAKING THE ANTIBIOTIC FOR 1 WEEK.BUT AFTER THAT SHES STILL HAVING COUGH BUT MAYBE IN ONE DAY SHE WILL JUST HAVING COUGH MAYBE 5 TIME  <response>: Hi, welcome to Chat Doctor forum. Usually, we do a sputum AFB to rule out tuberculosis if cough persist more than 2-3 weeks. But, since she responded to treatment, and cough has come down, we can try a cough suppressant like dextromethorphan, and antihistamines for 5-7 daysI guess she has no feveryellow sputum. It may help. If cough still persist, you please see your doctor and do sputum examination.Meanwhile, avoid dustycold environment. I hope you will find this information useful. Thank you. 