EXPANDED CLINICAL OBSERVATIONS IN TOXICITY STUDIES - HISTORICAL PERSPECTIVES AND CONTEMPORARY-ISSUES

Recent or proposed changes in major testing guidelines require expande d clinical observations (ECOs) for a wide variety of toxicity studies in animals. ECOs supplement the simple cageside and hand-held observat ions traditionally employed during such studies. The new guidelines sp ecify out-of-cage observations [e.g., posture, gait, and reactivity to various stimuli (e.g., auditory, tactile, noxious)] using defined sca les and are intended as a Tier 1 screen for neurotoxicity. These new g uidelines imply an elevation in the status of clinical observations to equivalency with other major categories of toxicity end points, such as anatomic and clinical pathology. The increased importance of neurol ogical end points in routine studies indicates that there will be a ne ed for many trained professionals to generate and interpret the result s of ECOs, However, currently there is wide variation in the training and experience of individuals who conduct and interpret ECOs. The valu e of ECO data will be increased when industry standards for conducting and interpreting ECOs are systematized and elevated to the level of t hose for anatomic and clinical pathology. (C) 1998 Academic Press.