Primary observation (Irwin) test in rodents for assessing acute toxicity of a test agent and its effects on behavior and physiological function.

The Irwin observation test is commonly used to evaluate the effects of a new substance on behavior and physiological function. The results of the Irwin test are used to determine potential toxicity and to select doses for specific therapeutic activity. The Irwin test can also be used in a safety approach for detecting untoward effects of a new compound on general behavior and for evaluating its acute neurotoxicity. In particular, data obtained in the Irwin Test can help to determine the dose range to be tested in other safety tests. Furthermore, the Irwin Test can furnish a first but pertinent orientation towards a specific therapeutic indication, a specific mechanism of action or a specific physiological function.