Substances dataset | Dose metric | Stage of development | Results | Reference |
---|---|---|---|---|
Animal data | ||||
238 chemicals | LD50 | Adult and newborn mammals | Median LD50Adult/LD50Newborn = 2.6 | [70] |
14% of ratios exceeded 10 | ||||
18 industrial chemicals | pNOAEL | Young and newborn rats (postnatal days 4 to 21) | NOAELYoung/NOAELNewborn < 5 for 17 of 18 chemicals | [98] |
Human data | ||||
15 anticancer drugs | MTD | Adults and children | 1.3 < Mean MTDChild/MTDAdult <4.1 | [99], ratio of equivalent doses in mg/kg calculated by Dourson et al. [100] |
24 drugs | Hepatic clearance (Cl) or half-life (HL) | Adults and newborns | Cl or HLNewborn/ Cl or HLAdult > 3.2 for 33% of drugs | |
22 substances | Toxicokinetic parameters | Adults and children and/or newborns | 3.2 subfactor for toxicokinetics intraspecies differences adjusts the adult parameter to that of the infant or child for 91% of substances. | |
313 substances (mostly pharmaceuticals) | LD50 | Adults and children | 14% of LD50Adult/LD50Child > 10 | [102] |
6 drugs | Toxicokinetic parameters (one toxicodynamic) | Adult and children | Ratio of mean adult parameter to lower 95% value of children varied between 0.6-3.7. | [92] |
Composite ratios all below 10 | ||||
44 drugs | Half-life | Adult and children in different age groups | Proportion of children whose half-life exceed 3.2-fold the adult mean value; | [94] |
0–1 week premature: 70% | ||||
0–1 week full term: 26% | ||||
1 week- 2 months: 27% | ||||
2 months-18 years: 0% |