The value of acute toxicity studies to support the clinical management of overdose and poisoning: A cross-discipline consensus
ABSTRACT Acute toxicity studies are no longer required to support first clinical trials of pharmaceuticals in man. However, it is unclear in the wording of the revised ICH M3 whether acute toxicity studies are required later in drug development (e.g., phase 3) in order to support the management of overdose. The NC3Rs held a workshop in January 2010 with representatives from international poison centres, the pharmaceutical and chemical industries, and regulatory and government bodies to explore further whether acute toxicity studies are used to support the clinical management of overdose of pharmaceuticals and whether this work can be translated to other sectors such as the chemical industry. The consensus formed at the workshop was that acute toxicity studies are not used for managing overdose of pharmaceuticals and are of little value in treating human poisoning from chemicals. In this paper, the authors describe the key considerations in treating human overdose and poisoning, challenge the value of the classification and labelling process of chemicals for this purpose and discuss how acute toxicity studies can be improved to better inform risk assessment.
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ABSTRACT: Short term toxicity studies are conducted in animals to provide information on major adverse effects typically at the maximum tolerated dose (MTD). Such studies are important from a scientific and ethical perspective as they are used to make decisions on progression of potential candidate drugs, and to set dose levels for subsequent regulatory studies. The MTD is usually determined by parameters such as clinical signs, reductions in body weight and food consumption. However, these assessments are often subjective and there are no published criteria to guide the selection of an appropriate MTD. Even where an objective measurement exists, such as body weight loss (BWL), there is no agreement on what level constitutes an MTD. A global initiative including 15 companies, led by the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), has shared data on BWL in toxicity studies to assess the impact on the animal and the study outcome. Information on 151 studies has been used to develop an alert/warning system for BWL in short term toxicity studies. The data analysis supports BWL limits for short term dosing (up to 7 days) of 10% for rat and dog and 6% for non-human primates (NHPs).Regulatory Toxicology and Pharmacology 04/2013; 67(1). DOI:10.1016/j.yrtph.2013.04.003 · 2.14 Impact Factor
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ABSTRACT: A survey conducted on the EU Notification of New Substances (NONS) database suggested that for industrial chemicals with a profile of low toxicity in (sub)acute toxicity tests there is little added value to the conduct of the 90-day repeated dose study. Avoiding unnecessary animal testing is a central aim of the EU REACH chemicals legislation; therefore we sought to verify the profile using additional data. The OECD's eChemPortal was searched for substances that had both a 28-day and a 90-day study and their robust study summaries were then examined from the ECHA CHEM database. Out of 182 substances with high quality 28-day and 90-day study results, only 18 reported no toxicity of any kind in the (sub)acute tests. However, for 16 of these there were also no reported signs of toxicity at or close to the limit dose (1,000 mg/kg bw/d) in the 90-day study. Restricting the 'low (sub)acute toxicity in a high quality dataset' profile to general industrial chemicals of no known biological activity, whilst allowing irritant substances, increases the data set and improves the prediction to 95% (20 substances out of 21 substances). The low toxicity profile appears to be of low prevalence within industrial chemicals (10-15%), nevertheless, avoidance of the conduct of a redundant 90-day study for this proportion of the remaining REACH phase-in substances would avoid the use of nearly 50,000 animals and save industry 50 million Euros, with no impact on the assessment of human health.Regulatory Toxicology and Pharmacology 04/2014; 69(3). DOI:10.1016/j.yrtph.2014.04.008 · 2.14 Impact Factor
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ABSTRACT: Tomato and tomato products are considered to be healthy food for the human diet. Although tomatoes have been widely studied for their phenolic content, less emphasize has been laid on toxicological effect of this plant. Thus, the purpose of the present study is to determine the acute toxicity effect of Lycopersicon esculentum, or commonly known as tomato, was administered orally in the form of dried tomato pomace extract in vivo. Adult male rats were orally administrated single dose of 1000 and 5000 mg kg −1 dried tomato pomace extract. There were 10 rats in each group. All animals were sacrificed after 2 weeks of treatment. Seven parameters were tested: cage side observation, body weight gain measurement, food and water consumption, absolute organ weight, hematology, biochemical analysis and histopathology, to look for evidence of acute toxicity. No mortality was observed when varying doses of the extracts were administered per day for a period of 2 weeks. There were no significant differences in body weight, behavior, food consumption, absolute organ weights between controls and treated animals. Hematological analysis showed no differences in most parameters examined. In the biochemistry parameter measurement, no significant change occurred. Pathologically, neither gross abnormalities nor histopathological changes were observed. These finding suggest that none of the organs appeared to be target and the data could provide satisfactory preclinical evidence of safety to launch clinical trial on standardized formulation of tomato pomace extracts to be the dietary supplement.OnLine Journal of Biological Sciences 05/2013; 132834(13):28-34. DOI:10.3844/ojbssp.2013.28.34