An automated drug delivery and monitoring system for use on mechanically ventilated patients in the intensive care unit is presented. Medication in the form of respirable particles is transported through ventilator circuitry by a delivery unit. Multiple medications may be delivered into the gas flow of the ventilator, with each medication delivered in a defined dose for a frequency and interval as specified by an operator. The particles mixed into the gas flow of the ventilator are inhaled and ingested by the patent's lungs.