Phil Howard has received an e-mail from Alison Thomson, a lecturer at Strathclyde school of pharmacy regarding vancomycin and gentamicin.  The scottish antimicrobial prescribing group have a vancomycin calculator, a copy of which we have on this site.

They use the concept of "maximum body weight” (IBW + 20% if the patient is > 20% above IBW) when estimating CrCl. And their guidance for these two drugs is available at

http://www.scottishmedicines.org/files/sapg/Vancomycin_Calculator_050110.xls

They also have a gentamicin calculator, but it is on a different regimen to Hartford.  If you want a look at what can be done it's here:

http://www.scottishmedicines.org/files/sapg/Gentamicin_Calculator_110210.xls