A host controller (10) selectively predicts and controls drug concentrations for each of a plurality of channels delivered through multiple drug channels of a multi-channel drug delivery system. The host controller includes a controller (32) that is coupled to each drug channel of the multi-channel drug delivery system to receive actual drug delivery rate information. Delivery of each drug can be selectively separately controlled by a PK model (the same PK model for each channel or different PK models for different channels) to achieve either a desired setpoint for a blood plasma drug concentration or a setpoint for an effect compartment drug concentration. Control of the drug delivery by the PK model can be selectively interrupted during operation of the multi-channel drug delivery system, to switch to a manual mode in order to administer a bolus dose or a continuous infusion, and then, control of drug infusion using the PK model can be subsequently resumed. The blood plasma and/or effect compartment drug concentrations for any drug predicted in accordance with a PK model are selectively displayed to a user on an electroluminescent (EL) display (36), even during operation of the multi-channel drug delivery system in the manual mode, or after the drug delivery has been terminated. Prediction of drug concentration is tracked for each drug administered, enabling multiple drugs to successively administered in the same drug channel and control of a drug delivery by the PK model to continue when the drug channel used to administer the drug is changed.