This combination of drugs is an oral antibiotic widely used to treat mild to moderate bacterial infections.
This combination is currently the most common cause of clinically apparent acute hepatic injury induced by drugs, both in the United States and in Europe.
The combination consists of amoxicillin, semisynthetic third-generation penicillin, and clavulanate, a beta-lactam that acts as a beta-lactamase inhibitor.
The main bacterial enzyme is responsible for resistance to penicillin.
Amoxicillin clavulanate was approved for use in the United States in 1984, and, currently, 2 to 5 million prescriptions are filled annually, making it one of the most commonly used antibiotic regimens.
Current indications are for mild to moderate bacterial infections due to known or suspected gram-positive or gram-negative organisms resistant to penicillinase.
This combination is provided in multiple-dose combinations, typically 250 to 875 mg of amoxicillin with 125 mg of clavulanate, two to three times a day for 7 to 10 days.
Amoxicillin clavulanate is available in multiple generic formulations and under Augmentin’s brand name. Common side effects include gastrointestinal upset, diarrhea, and rash.
Amoxicillin clavulanate has been implicated in hundreds of clinically apparent acute liver injury cases.
This combination is currently the most common cause of drug-induced liver disease in most large cases in the United States and Europe.
The onset of the injury usually lasts a few days or up to 8 weeks, after the start of therapy often occurs after the antibiotic cycle is completed; the delay is a few days or up to six weeks.
The onset is usually fatigue, low fever, nausea, and abdominal pain, followed by pruritus and jaundice.
The pattern of elevations of liver enzymes is typically cholestatic, with marked elevations in alkaline phosphatase and gamma-glutamyl transpeptidase.
In some cases, aminotransferase levels are markedly elevated, giving a mixed or hepatocellular pattern, particularly in younger patients with an earlier lesion onset.
In children, amoxicillin-clavulanic hepatotoxicity is typically anicteric and occurs with nausea, vomiting, and abdominal pain instead of jaundice and itching.
The pattern of elevated serum enzymes is also much more likely to be hepatocellular in children, but the course of the disease is usually benign.
Because liver injury can occur days or weeks after stopping treatment, the association of liver injury with the reception of amoxicillin / clavulanic acid may go unnoticed.
Immunoallergic features (fever, rash, eosinophilia ) may occur, but they are not invariably present and are generally not prominent.
The formation of autoantibodies is not typical. The liver injury is idiosyncratic and is estimated to occur after one week in 2,500 prescriptions. Damage is more common in men than in women, the elderly, and after multiple courses.
The cause of amoxicillin-clavulanic hepatotoxicity is unknown but probably of allergic immune origin.
Allergic manifestations can include rash, fever, arthralgias, and eosinophilia.
An independent HLA Class I association has also been made with HLA-A * 02: 01. The liver injury appears to be due to clavulanate rather than amoxicillin since reexposure to amoxicillin alone has not been associated with recurrence.
While reexposure to the combination is often followed by a more rapid onset of a more severe liver injury that may include prolonged cholestasis and the development of cirrhosis.
Other beta-lactamase inhibitors (tazobactam and sulbactam) have not been reported to cause a similar hepatic injury.
Although it has been reported with other penicillins when combined with clavulanate (ticarcillin/clavulanate).
Result and management
Hepatic injury caused by amoxicillin-clavulanate is typically associated with jaundice and can be severe and prolonged (with jaundice lasting from 4 to 24 weeks).