Adverse drug reactions in liver cirrhosis

Impaired liver function may increase susceptibility to drug toxicity. In a prospective drug surveillance study of 1280 patients the frequency of adverse drug reactions (ADR) was higher in 333 patients with clinical and/or histopathological evidence of liver cirrhosis than in 188 with other liver diseases (p<0.01) and than in 759 without liver disease (p<0.0001). The 128 cirrhotics had 339 events considered definitely or probably related to drug therapy by consensus of the monitoring team and the attending physicians. ADR were 93.8% dose-related, 11.2% were severe but only one was fatal. ADR were most commonly associated with diuretics (32.6% of patients administered the drugs), potassium salts (6.5%), antimicrobials (3.9%) and sedatives (3.5%). Most common manifestations were metabolic (62.6%), gastrointestinal (13.2%) and neurologic (11.9%). The frequency of ADR was higher in females (p<0.05), patients receiving more drugs (p<0.001), those with longer hospital stay (p<0.001) and those with ascites (p<0.0001), portal hypertension (p<0.0001), prior hepatic encephalopathy (p<0.02) or prolonged prothrombin time (p<0.0001). Adverse reactions were more common for drugs biotransformed greater than 50% by the liver (p<0.005). These findings show that ADR are more frequent in severe hepatic dysfunction.