Drug-Induced Hepatitis – Top USMLE Diseases

Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF). Hepatotoxic drugs can cause dose-dependent, direct liver injury or idiosyncratic reactions mediated by immune or metabolic processes. This injury can result in hepatitis, cholestasis, steatosis, or overlapping changes. The presentation can be acute or chronic, with severe toxicity manifesting as fulminant liver failure. The diagnosis of DILI requires a thorough history, liver function tests, and drug levels, if available. Management consists of discontinuing the drug, supportive therapy, and monitoring for complications. Acetaminophen is the most common cause of DILI and is treated with a specific therapy, N-acetylcysteine (NAC).

Liver function tests, also known as hepatic function panels, are one of the most commonly performed screening blood tests. Such tests are also used to detect, evaluate, and monitor acute and chronic liver diseases. Liver function tests assess the levels of various hepatic proteins and enzymes to determine the state of liver metabolic activity, homeostasis, bile metabolism, and protein synthesis capacity. The standard hepatic panel includes the levels of total protein, bilirubin, albumin, ALT, AST, AST/ALT ratio, and alkaline phosphatase (ALP).

Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF). Hepatotoxic drugs can cause injury to the hepatocytes directly in a predictable dose-dependent way or through idiosyncratic reactions (which may be mediated by immune or non-immune processes). The injury mechanisms can have the following effects: hepatitis, cholestasis, vascular lesions, or overlapping changes. The presentation can be acute or chronic, with severe toxicity manifesting as fulminant liver failure. The diagnosis of DILI requires a thorough history and laboratory tests including liver function tests (LFTs) and drug levels, if available. Management consists of discontinuing the drug, supportive therapy, and monitoring for complications. Acetaminophen, 1 of the most common causes of DILI, has a specific treatment, N-acetylcysteine (NAC).