What signs of liver problems mean we should stop the drug?

The short version: jaundice, dark urine, or a rising ALT or bilirubin on blood work means stop the drug immediately.

Amoxicillin-clavulanate is the single most common cause of drug-induced liver injury in several registries. In the Icelandic population study, it accounted for 22% of all DILI cases [4]. The injury is usually cholestatic—meaning bile flow slows—and it can appear weeks after the drug is stopped, which makes it easy to miss [3].

The clinical signs that should make you stop are straightforward. Jaundice (yellowing of the skin or eyes) and dark urine are the most visible. Fatigue, nausea, and loss of appetite often come with it. In the case series from 1989, the average time from starting the drug to the first symptom was 10 to 35 days, and peak bilirubin levels ranged from 7 to 44 mg/dL [3]. In the 2003 case report, the patient's ALT jumped from 154 to 972 U/L and alkaline phosphatase from 120 to 358 U/L after treatment [5]. That pattern—a sharp rise in liver enzymes after the drug is started—is the laboratory signal.

The mechanism is not a simple overdose. It is an immune-mediated hypersensitivity, linked to specific HLA types like HLA-DRB1*15:02 [2]. That means some people are genetically susceptible, and the injury can happen at normal doses. The clavulanate component is the main driver: Italian spontaneous reporting data showed that the combination caused 4% of all reported adverse reactions and those were flagged as serious, while plain amoxicillin caused only 1% and none were labeled serious [1].

The tricky part is timing. The injury often appears after the course is finished, so a patient who finished the antibiotic a week ago and now feels sick may not connect it. If you took this drug and develop any of those signs, stop the drug and get a liver panel drawn. Most cases resolve after stopping, but the recovery can take weeks to months [3].

My call: Stop the drug at the first sign of jaundice, dark urine, or a lab-confirmed ALT or bilirubin rise above 2-3 times normal. Confidence: high. The association is well-documented across multiple registries and case series, and the mechanism (immune-mediated, HLA-linked) is biologically plausible.