Cough aggravated after injection of penicillin, may be the drug is not symptomatic or the drug is not sensitive. Cough is clinically common in respiratory tract infections, allergies, food reflux, lung cancer and other conditions, and should be selected for the cause of the drug treatment. 1. Respiratory tract infection: cough aggravated after injection of penicillin, may be penicillin insensitive bacteria, or special pathogens such as tuberculosis, fungi, viruses, mycoplasma, legionella and other infections, the application of penicillin is ineffective. The corresponding anti-infection program should be given in combination with the pathogen. 2. Allergy: contact with allergens leads to allergic cough caused by allergy, if you can’t get rid of the allergens in time, injection of penicillin may aggravate the condition, you should follow the doctor’s instructions to apply cotrimoxazole, loratadine and other drugs. 3. Food reflux: patients suffering from reflux esophagitis, food reflux repeatedly stimulates the throat leading to cough symptoms, which may be aggravated after applying penicillin, and they should follow the doctor’s instruction to take Pantoprazole, Mosapride and other drugs. 4. Lung cancer: patients with lung cancer are prone to cough symptoms, which may be accompanied by blood in sputum, and the application of penicillin is ineffective, and it is necessary to assess the histological type and tumor staging, and give individualized treatment plan. There are many reasons for coughing, and antibiotics can not be used arbitrarily. If the symptoms worsen after penicillin injection, patients should go to the hospital in time to find out the reasons and use medicines reasonably under the guidance of doctors.