Zithromax, though popular for its short course, may in rare cases lead to liver complications that threaten the patient with severe harm and sometimes death.

Generic azithromycin first got FDA approval under the name Zithromax in November 1991. It’s now approved for treatment of various bacterial infections that affect the skin, respiratory and genitourinary systems. Zithromax is often sold under the name Zmax and in a five-day course known as a Z-Pak.

Pfizer Inc., the maker of Zithromax, has enjoyed ample profits from Zithromax sales. Sales peaked at $2 billion in 2005, before Pfizer’s patent for Zithromax expired and allowed generics to enter the market and compete. Even then, Zithromax sales remained vigorous, totaling $435 million in 2012.

Zithromax Liver Damage

In 2010, the FDA noted a potential safety issue based on the number of reports of liver failure associated with Zithromax treatment received in the agency’s adverse event report system. In January 2011, the FDA updated the warning label for Zithromax to include a warning about liver failure.

The current FDA-approved label for Zithromax warns that “[a]bnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure” have been reported in association with Zithromax treatment, and some such cases have resulted in death.

The label advises patients taking Zithromax to contact their physician immediately if they experience yellowing skin or whites of the eyes, or if their urine becomes dark. These can all be signs of Zithromax liver damage.

Other symptoms of liver failure include abdominal pain, swelling in the lower legs, itching, fatigue, nausea, vomiting, loss of appetite, or tendency to bruise easily.

As with all macrolide antibiotics, the body relies on the liver to metabolize Zithromax. Therefore, patients who have preexisting liver trouble may be at greater risk for Zithromax liver damage.

Zithromax liver side effects that lead to full-blown liver failure expose the patient to tremendous risk of harm and death, since the body relies on the liver for a host of life-sustaining functions.

With liver failure, the liver may not be able to manufacture the proteins that allow blood to clot, exposing the patient to the risk of excessive bleeding. The organ also fails to process the waste product bilirubin, leaving it deposited in the skin.

Even brain function may be harmed due to the increase of toxins in the blood that the failing liver can no longer process, resulting in a condition called hepatic encephalopathy. The immune system as a whole may also be compromised. And for reasons not yet scientifically understood, up to half of patients who suffer liver failure also suffer kidney malfunction, a condition called hepatorenal syndrome.

Treatment may require efforts as extreme as a liver transplant, in cases where the liver simply no longer functions on its own. Success with transplantation varies a lot: a large majority of recipients survive for at least one year. If the transplant is performed soon enough, some patients live as long as they might have without a liver disorder.

In cases of acute liver failure, in which the patient is in particularl imminent danger, treatment may include any number of methods depending on which of many complications develop. Infections may require antibiotics; fluids may need to be replaced; low blood sugar may require intravenous glucose; and excess bleeding may require blood transfusion.