Related Experiment Video
Updated: Aug 5, 2026
07:08
Long-term Behavioral and Reproductive Consequences of Embryonic Exposure to Low-dose Toxicants
Published on: March 6, 2018
Evaluation of biologically based dose-response modeling for developmental toxicity: a workshop report
C Lau1, M E Andersen, D J Crawford-Brown
1Reproductive Toxicology Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
Regulatory Toxicology and Pharmacology : RTP
|June 15, 2000
Summary
Biologically based dose-response (BBDR) modeling offers a novel way to assess health risks by integrating biological mechanisms. However, this approach is data-intensive and costly, requiring further research to determine its full potential in reducing uncertainty.
Area of Science:
- Toxicology
- Pharmacology
- Biomathematics
Background:
- Biologically based dose-response (BBDR) modeling advances quantitative health risk assessment by integrating pharmacokinetic and pharmacodynamic data.
- This approach links cellular responses to adverse outcomes through a cascade of biological events.
- Mathematical models describe these intervening events, allowing for dose and species extrapolation.
Framework:
- The U.S. Environmental Protection Agency's Reproductive Toxicology Division explored BBDR modeling feasibility.
- Developmental toxicity of 5-fluorouracil was examined as a case study.
- A workshop convened experts to evaluate the EPA's approach and discuss BBDR modeling's future.
Implementation:
- The study assessed the feasibility of incorporating mechanistic information into quantitative dose-response models.
- Challenges include the data-intensive and costly nature of BBDR modeling.
- Model confidence is directly linked to current biological understanding and ongoing discoveries.
Implications:
- BBDR modeling shows potential for health risk assessment by using mechanistic data.
- Further research is needed to compare BBDR modeling with traditional methods like NOAEL and benchmark approaches.
- The extent to which BBDR modeling can reduce uncertainty requires additional scrutiny.
Related Concept Videos
01:03Dose-Response Relationship: Overview
Agonists can bind with and activate receptors, resulting in the formation of drug-receptor complexes. Once formed, these complexes catalyze many biochemical processes at the cellular level and subsequently induce a pharmacologic response. The degree of response is directly proportional to the fraction of activated receptors, which in turn, depends on the concentration of the drug at the receptor site as well as the sensitivity of the receptor. An increase in the administered dose contributes to...
01:26Pharmacokinetic–Pharmacodynamic Relationship: Exposure, Response and Effect
The pharmacokinetic-pharmacodynamic (PK-PD) relationship describes the intricate link between drug exposure, efficacy, and toxicity, forming the foundation for optimal dosing regimens. This relationship uses mathematical modeling to characterize drug concentration-effect dynamics, ensuring precise therapeutic outcomes.Exposure represents the pharmacokinetic aspect of the PK-PD relationship, denoting the drug amount that elicits a biological response. It is typically quantified by administered...
01:27Pharmacodynamic Models: Overview
Pharmacodynamic (PD) responses describe the interaction between a drug and its biological target, culminating in a physiological effect. These responses can be classified into different types: continuous variables, such as blood glucose levels; categorical outcomes, like survival rates; and time-to-event metrics, such as disease progression. Understanding and modeling PD responses are critical for optimizing drug efficacy and safety.PD models describe the relationship between drug concentration...
01:21Dose Response Curve: Conventional Versus Nonmonotonic
The correlation between a drug's dosage and its impact on a biological system is a cornerstone of pharmacology and toxicology. Conventional dose–response curves, which include graded and quantal relationships, are key to this understanding. Graded dose–response curves depict the spectrum of a biological reaction to different doses within an individual, indicating that as the drug dosage increases, so does the intensity of the response. On the other hand, quantal dose–response relationships...
01:21Toxicokinetics: Overview
Studies that assess how a drug is absorbed, distributed, metabolized, and excreted (ADME) at toxic doses are termed toxicokinetics. Understanding toxicokinetics helps predict adverse drug reactions (ADRs) and manage toxicity in humans.Toxicokinetics differs from pharmacokinetics mainly in the dose levels studied, with toxicokinetics focusing on higher toxic doses. The kinetics at these levels can be non-linear due to altered physiological processes. Toxicodynamics examines the relationship...
01:23Toxicity Testing in Animals
Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...