text: calculating volume of distribution of a drug? i am trying to work out the half life and volume of distribution of a drug, as part of exam revision. i have a table giving the conc. of drug in the plasma (ng per ml) at set times after dosing. we have been told that the drug was administered at 0.1mg per kg. please help! btw - the data was gained using rats. drug  for calculations for nurses by robert lapham and heather agar might help your revision