Hello, I read carefully your query and understand your concern. A persistent cough may be caused by a long-term respiratory tract infection, such as chronic bronchitis. I suggest to do a chest xray for further evaluation. Meanwhile,I suggest to continue the cycle of antibiotics. I also suggest using a decongestant for the dry cough such as Dexometorphan. I recommend to rest and drink liquids. Hope my answer was helpful. If you have further queries feel free to contact me again. Kind regards! Dr.Dorina Gurabardhi General &Family Physician