DRUG INDUCED LIVER DISEASE

Liver impairment can be caused by a significant number of foreign compounds (xenobiotics); prescribed drugs, ‘over the counter’ (OTC) drugs, herbal and alternative medicines. Hepatotoxicity caused by drugs used for therapeutic, recreational or nutritional purposes as well as drugs of abuse is a drug-induced liver disease (DILD). Over 300 agents in use have been connected with causing DILD. Factors associated with increased susceptibility to DILD are: age, gender, genetic predisposition, dose, other drug reactions, concomitant use of drugs, excessive use of alcohol, nutritional status, liver disease and other diseases. Drugs may cause liver injury in a predictable, dose-dependant manner (intrinsic DILD), or in an unpredictable, non-dose-dependant manner (idiosyncratic DILD). Xenobiotics that cause liver impairment provide a wide range of lesions resembling many other liver diseases. Acute hepatocellular damage can be cytotoxic (hepatocellular necrosis), cholestatic (associated with the interrupted flow of bile), or mixed. Clinical expressions of DILD range from nonspecific abnormalities of liver tests, to cholestasis, acute hepatitis and acute liver failure. Nodular hyperplasias, chronic hepatitis, autoimmune hepatitis, fibrosis, NASH, cirrhosis, benign and malignant liver tumours have been reported. Diagnosis of DILD is based on history, blood tests, imaging examination of hepatobiliary tract and, if applicable, liver biopsy. Clinical and laboratory findings in DILDs are not always in line with liver pathology. Histologic changes can be minor compared to biochemical findings. Liver enzymes are not synonym of liver damage