Zithromax is a widely used antibiotic that is most often used to treat bacterial sinus infections in adults and ear infections in children. Made by Pfizer, Zithromax was approved by the U.S. Food and Drug Administration (FDA) in 1992. Most antibiotics are taken for 10 to 14 days; however, Zithromax is usually prescribed in a five-day dose.
The most typical side effects associated with Zithromax include diarrhea, nausea, abdominal pain, or vomiting. At times, the diarrhea me be clostridium difficile-associated diarrhea, referred to as CDAD. This sort of diarrhea may occur because, aside from eliminating bacteria, the antibiotic affects the normal flora of the colon. This leads to an overgrowth of C. difficile. On occasion this side effect may occur more than two months after the antibiotic has been taken.
Other potential and serious Zithromax side effects include liver problems or liver damage such as acute hepatic injury, which is inflammation of the liver (yellowing of the skin and eyes); dark urine; extreme fatigue; nausea; fever; vomiting; abdominal pain; liver necrosis; and liver failure. Zithromax is a macrolide antibiotic, and antibiotics in this class are flushed from the body through the liver. Liver damage may deteriorate to liver failure which may result in the need for a liver transplant, or even death.
According to the National Institutes of Health (NIH), in 1997, a 69-year-old man took 500 mg. of Zithromax to treat pneumonia. After taking Zithromax for only three days, he stopped the medication and three days after he stopped taking the antibiotic, he produced dark urine and his eyes and skin became jaundiced. Laboratory tests revealed that he had increased bilirubin levels, but was negative for hepatitis A, B, and C viruses. Nothing unusual was found on his liver ultrasound. He was then given a different antibiotic to treat the pneumonia, and recovered within a few weeks.
The man recovered relatively quickly; however, doctors agreed that he was probably lucky that he took Zithromax for only three days. The man was advised by medical staff not to take Zithromax in the future, but could not say for certain if he should take another macrolide antibiotic, such as erythromycin.