Decision information systems, methods, and computer programs for better
informing decisions to use multiple drugs in drug delivery devices, including implantable
devices, for drug administration. Executable computer programs and logic embodying
methods of the invention can calculate consistent multiple drug mixture amounts
and drug delivery flow rates. One program accepts user input indicating a desired
first drug dose rate, an initial first drug concentration, a desired second drug
dose rate, an initial second drug concentration, and the reservoir size of the
drug delivery device. The program method calculates a first drug amount and a second
drug amount to combine in a mixture as well as a first drug true concentration
in the mixture. The drugs can be mixed consistent with the physician's instructions
using the program output. The first drug true concentration can be entered into
a programmer device as the only drug concentration entered. Another program calculates
a consistent first drug, second drug, and diluent amount to be added to a mixture
for injection into a fixed flow rate, implantable drug delivery device. Methods
preferably output true concentrations and dose rates for all drugs to be added
and most preferably show all calculations used to arrive at the flow rate and mixture
amount calculations. Yet another program receives a new desired drug dose rate
for a previously filled device. The program accepts the existing mixture volume
and true drug concentrations for a partially depleted device and calculates a new
mixture flow rate to achieve the desired dose rate using the existing mixture.
The methods can be implemented as executable computer programs in programmer devices,
general purpose computers, servers, handheld computers, and personal digital assistants.
