Toxicology of Industrial Compounds

Body surface area (BSA)
It has been suggested that the body surface area provides a good measure
of overall metabolic rate and that this may be a better measure of relative
clearance between species (Chiou and Hsu, 1988). The BSA has therefore
been cal culated for each species using Meehs Formula, BSA=0.103·W 0.67
(Spector, 1956) and the ratio of human BSA to animal BSA multiplied by
the animal clearance, to determine the predicted human clearance.
Life span correction
D.BRUCE CAMPBELL 47
Figure 4.1. Allometric scaling of Fotemustine clearance compared with the body
weight in various species.
For some drugs, particularly those which are extensively metabolised but
have a low hepatic clearance, such as phenytoin, antipyrine or caffeine
(Boxenbaum, 1982b; Bonati et al., 1984–5), these simple scaling methods
seem to be poorly predictive for man and an allometric correction using
maximum life potential (MLP) has been used to improve the accuracy
(Figure 4.2). Although the allometric approach using body weight alone is