Hello nidhi.behere, Thank you for visiting Healthcaremagic.com. Azithromycin is used to treat certain infections caused by bacteria, such as bronchitis; pneumonia; sexually transmitted diseases (STD); and infections of the ears, lungs, skin, and throat. Azithromycin is in a class of medications called macrolide antibiotics. It works by stopping the growth of bacteria. Antibiotics will not work for colds, flu, or other viral infections. It is usually taken with or without food once a day for 1-5 days. Cefixime is a cephalosporin antibiotic used to treat infections caused by bacteria such as pneumonia; bronchitis; gonorrhea; and ear, lung, throat, and urinary tract infections. Antibiotics will not work for colds, flu, or other viral infections. It is usually taken once a day or every 12 hours (twice a day) for 5-14 days. Normally, an antibiotic is not changed until you have failed the course of the first antibiotic. Because you took only one tablet of the azithromycin, I would suggest additional tablets be taken. You state that you must travel tomorrow, which means it would be difficult to get in to see a doctor. In that case, if you have access to Cefixime 250 mg, you may take that twice a day for 7 full days. You may take ibuprofen and tylenol to manage symptoms of pain and fever. If you are still experiencing symptoms of your illness after 7 days, please visit a physician for further treatment. Be well, Dr. Kimberly