Hepatic reactions to drugs.

Focus in this progress report on heatpic rections to drugs is on mechanisms of drug hepatotoxicity (direct -- metabolite-related -- factors immunological factors) hepatotoxic substrances (carbon tetrachloride paracetamol methotrexate other cytotoxic drugs isoniazid rifampicin methyl dopa halothane chlorpromazine and other drugs) sex hormones (cholestasis) sex hormone tumors and androgenic hormones. The liver is particularly concerned with drug metabolism and particularly with drugs administered orally. These must be lipid soluble to have passed the membrane of the intestinal cell and must be converted to water soluble compounds for excretion via the urine or bile. The primary drug metabolising system resides in the microsomal fraction of the liver cell. Factors determining whether the metabolised drug will be excreted ultimately in bile or urine are multiple and many are unclear. Factors determining the effect of drugs include age parenchymal liver disease biliary excretion previous drug administration the enterohepatic circulation and the gut flora.