1. A control for a multi-channel drug delivery system with which a plurality of drugs are selectively administered to a patient through a plurality of drug channels in accordance with a PK model, comprising: (a) a processor that is controlled in accordance with a set of program instructions that determine the steps implemented by said PK model; (b) a memory, coupled to the processor, said memory storing the set of program instructions and a plurality of parameters used by the PK model; (c) a display, coupled to the processor, on which are displayed the parameters and PK model data, including a concentration of a drug within the patient as a function of time; (d) a user interface, coupled to the processor, said user interface enabling a user to input at least some of the plurality of parameters used by the PK model in controlling administration of each drug to the patient, and including identification means for identifying the drug that is being administered in each of the drug channels; and (e) PK model prediction means, embodied in the processor executing said set of program instructions, for determining a drug concentration within the patient over time for each drug, as each drug is administered by the multi-channel drug delivery system, said PK model prediction means determining the drug concentration: (i) during any interruption and after a termination of the drug delivery; and (ii) regardless of any change in the drug channel through which any drug is delivered.