KINETIC AND DYNAMIC DATA OF ANALGESICS AND NSAIDS DRUGS REDUCE 10X UNCERTAINTY FACTORS

The risk assessment process must use all available toxicological data and scientific evidence on the adverse effects of chemicals or drugs. The relationship between biological indicators and exposure or tissue burdens is determined by the pharmacokinetic and pharmacodynamic behav ior of the chemical. The purpose of the present project was to investi gate the use of pharmacokinetic and pharmacodynamic data in reducing t he uncertainties in establishing exposure levels for some analgesics a nd non-steroidal anti-inflammatory drugs (NSAIDs). Five pharmaceutical s were evaluated, namely: naproxen, acetaminophen, aspirin, ibuprofen and ketoprofen. The pharmacokinetic and pharmacodynamic parameters in inter-and intra-species were evaluated. The composite factors for all the examined drugs were far less than 100. The present study indicated that the formation of data basis for different chemicals based on pha rmacokinetic and pharmacodynamic behavior is important in setting up e xposure levels, rather than the use of default uncertainty factors whi ch are in many cases imprecise.