Adults cough hang penicillin a few days after not relieved possible reasons are: penicillin failed to cover the pathogenic bacteria or bacteria resistant to penicillin, non-bacterial infections, tuberculosis, non-infectious diseases caused by cough. 1. Penicillin fails to cover pathogenic bacteria or bacteria resistant to penicillin: penicillin is not effective against all bacteria, and the bacteria that may cause the cough are not sensitive to penicillin. Secondly, penicillin resistance is very common in clinic, in the case of evidence of bacterial infection after using penicillin symptoms are not relieved should consider the possibility of drug resistance, it is recommended that sputum culture and drug sensitivity test to determine the sensitive antibiotics. 2. Non-bacterial infections: Penicillin as an antibiotic is only effective against bacterial infections, but not against non-bacterial infections such as viruses and fungi. 3. Tuberculosis: Tuberculosis is a special kind of lung infection, penicillin and other conventional antibiotic treatment is ineffective, need professional and strict anti-tuberculosis treatment, commonly used drugs are isoniazid, rifampicin and so on. 4. Cough caused by non-infectious factors: Cough can also be caused by certain non-infectious diseases, such as interstitial lung disease, cough variant asthma, lung cancer, etc., due to the disease to be treated accordingly. Adults with cough do not have relief after several days of penicillin, indicating that the current treatment program is ineffective, it is recommended that the patient as soon as possible to professional hospitals, as soon as possible to determine the cause of cough, to be targeted treatment.