Clinical diagnostic scale: a useful tool in the evaluation of suspected hepatotoxic adverse drug reactions

Background/Aim: Due to an absence of specific markers, the diagnosis of dru g-induced hepatotoxicity is necessarily based on circumstantial evidence an d is often inaccurate. We have evaluated the use of the clinical diagnostic scale (CDS) in the causality assessment of hepatotoxic adverse drug reacti on (ADR) reports. Methods: 135 hepatic adverse ADRs reported to the Committee on Safety of Me dicines in North East England 1992-6 were evaluated. Initially, "Internatio nal Consensus Criteria" were used to classify reactions as "drug-related", "drug-unrelated" and "indeterminate", Using the CDS, each ADR was then cate gorised as either definite drug hepatotoxicity (score >17), probable (14-17 ), possible (10-13), unlikely (6-9), or drug hepatotoxicity excluded (<6). Results: 49 ADRs were considered drug-related, 65 unrelated and 21 indeterm inate, Reports classified as drug-related by consensus criteria scored high er on the CDS, with a median score of 12, range: 8-15, than either the inde terminate (8; [3-12]) or drug-unrelated reports (5; [2-11]) (p<0.0001), A C DS score of >9, identified 88% of the cases classified as drug-related hepa totoxicity by consensus criteria and excluded 98% of those unrelated to the drugs. Conclusions: CDS scoring correlates web with the international consensus cl assification and may be a useful tool in the routine evaluation of suspecte d hepatotoxic drug reactions.