Detection and incidence of drug-induced liver injuries in hospital: a prospective analysis from laboratory signals

Aims Liver damage remains the most frequent type of adverse drug reaction ( ADRs) that can lead to the withdrawal of a drug from the market. The abnorm al laboratory data identified by computerized hospital information systems can be used in order to improve the detection of ADRs. Our objectives were to assess the detection and incidence of drug-induced liver abnormalities i n a university hospital inpatient population and to evaluate the underrepor ting rate of drug-induced liver injury. Methods We conducted a prospective study performed 1 week per month from Ju ne to October 1997. We selected patients by a computerized process using bi ochemistry laboratory data, based on serum enzyme values, alanine aminotran sferase (over 2 fold normal) and alkaline phosphatase (over 1.5 fold normal ). Results Among 1976 ALT and 1814 AP assays performed during the period of th e study, 156 (7.9%) and 159 (8.8%) tests, respectively, fell into the selec ted criteria. These concerne 147 patients. Among these patients, 13 (8.8%) cases of drug-induced liver injuries were suspected. Seven cases were asymp tomatic. Six cases were classified as serious by these criteria: hospitaliz ation to investigate the cause of health status impairment (4 patients), pr olongation of hospitalization (1 patient) and life-threathening (1 patient) . Using the hospitalization database, the incidence of drug-induced liver i njuries was estimated as 6.6 per 1000 inpatients a week. Only 1 case was re ported by physicians in the same period. Conclusions Computerization of biochemical data would allow the development of systems to improve detection of drug-induced injury. Moreover, underrep orting remains important for such potentially serious ADRs, even in a unive rsity hospital.