General derivation of the ideal intravenous drug input required to achieve and maintain a constant plasma drug concentration. Theoretical application to lignocaine therapy.

A constant plasma drug concentration can be achieved and maintained by the intravenous administration of an initial bolus loading dose in conjunction with a constant rate and an exponential intravenous drug infusion. The drug input required to achieve a constant plasma drug concentration is derived without making any assumptions about the nature of drug distribution within the body or elimination from the body.