Hepatotoxiska

Hepatotoxiska, or hepatotoxicity, describes liver injury caused by chemical substances or biological agents. It can be intrinsic, predictable and dose dependent, or idiosyncratic, unpredictable and not clearly dose related. The injury may be hepatocellular, cholestatic, or mixed, and can range from mild enzyme elevations to acute liver failure.

Most often caused by medications, including over-the-counter analgesics such as acetaminophen, antibiotics (for example amoxicillin-clavulanate, isoniazid), antiepileptics, and statins, as well as alcohol and illicit drugs. Herbal and dietary supplements, including some traditional remedies and high-dose green tea extracts, also contribute. Environmental toxins (aflatoxins, solvents) may cause hepatotoxic injury, particularly with chronic exposure.

Mechanisms include formation of reactive metabolites that damage hepatocytes, mitochondrial dysfunction, disruption of bile flow, and immune-mediated injury. Hepatotoxicity can present with jaundice, fatigue, abdominal pain, and abnormal liver tests: predominance of ALT/AST suggests hepatocellular injury; elevations in alkaline phosphatase and bilirubin suggest cholestasis. The pattern (hepatocellular versus cholestatic) is often summarized by the R factor.

Diagnosis relies on temporal association with exposure, exclusion of other causes, and assessment of causality using structured tools (such as the RUCAM score). In rare cases a liver biopsy is performed to characterize injury.

Management centers on stopping the offending agent and providing supportive care. Antidotes exist for certain toxins, most notably N-acetylcysteine for acetaminophen toxicity. Severe cases may require intensive care or liver transplantation. Prevention includes careful drug prescribing, avoiding unnecessary hepatotoxins, and monitoring liver tests during therapy when indicated.