Methods for delivering first and second fluid compositions to a target location of a subject include delivering the first composition from reservoir of an implantable infusion pump and delivering the second composition through a catheter access port of the implantable infusion device. The access port and reservoir are fluidly coupled to a catheter having a delivery region implanted in the target region. The methods more fully realize the therapeutic potential of infusion devices having both an access port and a reservoir. Strategic use of different agents that compliment the function of each other delivered via either the access port or the reservoir can result in enhanced therapeutic potential.