Zithromax (azithromycin) is prescribed for patients diagnosed with any infections caused by bacteria as well as a number of other condition s it may be recommended to treat. It will be inefficient against viral infections and is not supposed to be taken to treat them. It's important that you take the entire amount of this medicine prescribed without missing doses or skipping them. Your symptoms may get better before the infection has been completely treated. Stopping the treatment before it's time can cause a relapse of infection and more serious medications will be required. The following health conditions are supposed to be reported to your health care provider in case you have them or had at some point: kidney or liver disease, cystic fibrosis, human immunodeficiency virus, or irregular heartbeat. If you are currently taking digoxin, phenytoin, terfenadine, dihydroergotamine, ergotamine, anticoagulants, cyclosporine, medications that suppress the immune system, or nelfinavir, make sure your health care provider is aware of that fact. There is no need to get worried if you get such mild side effects as diarrhea, mild skin rash, stomach pain, vomiting, and upset stomach, as these go away on their own in most cases.