The common perception of scaling of dose based on the body weight (mg/kg) alone is not the right approach. This is primarily because the biochemical, functional systems in species vary which in turn alter pharmacokinetics. Therefore, extrapolation of dose from animals to humans needs consideration of body surface area, pharmacokinetics, and physiological time to increase clinical trial safety.
Human equivalent dose calculation based on body surface area*
*:Data obtained from FDA draft guidelines; HED:human equivalent dose
| Species | Reference body weight(kg) | Body surface area(m2) | To convert dose in mg/kg to dose in mg/m2, multiply by Km | To convert animal dose in mg/kg to HED in mg/kg, either | |
| Divide animal dose by | multiply animal dose by | ||||
| Human | 60.00 | 1.620 | 37 | - | - |
| Mouse | 0.02 | 0.007 | 3 | 12.3 | 0.081 |
| Hamster | 0.08 | 0.016 | 5 | 7.4 | 0.135 |
| Rat | 0.15 | 0.025 | 6 | 6.2 | 0.162 |
| Ferret | 0.30 | 0.043 | 7 | 5.3 | 0.189 |
| Guinea pig | 0.40 | 0.050 | 8 | 4.6 | 0.216 |
| Rabbit | 1.80 | 0.150 | 12 | 3.1 | 0.324 |
| Dog | 10.00 | 0.500 | 20 | 1.8 | 0.541 |
| Monkeys(rhesus) | 3.00 | 0.250 | 12 | 3.1 | 0.324 |
| Marmoset | 0.35 | 0.060 | 6 | 6.2 | 0.162 |
| Squirrel monkey | 0.60 | 0.090 | 7 | 5.3 | 0.189 |
| Baboon | 12.00 | 0.600 | 20 | 1.8 | 0.541 |
| Micro pig | 20.00 | 0.740 | 27 | 1.4 | 0.73 |
| Mini pig | 40.00 | 1.140 | 35 | 1.1 | 0.946 |
Human dose (mg/kg) to mouse dose (mg/kg) - multiply by 12.3
Human dose (mg/kg) to rat dose (mg/kg) - multiply by 7.4
Human dose (mg/kg) to guinea pig dose (mg/kg) - multiply by 4.6
Human dose (mg/kg) to rabbit dose (mg/kg) - multiply by 3.1
Human dose (mg/kg) to dog dose (mg/kg) - multiply by 1.8
References
Nair AB, Jacob S. A simple practice guide for dose conversion between animals and human. J Basic Clin Pharm. 2016;7(2):27–31. doi:10.4103/0976-0105.177703
Souce: NovoPro 2019-05-31