An implantable infusion apparatus has a medication reservoir for storing a medication and a carrier reservoir for storing a carrier. The entire apparatus, including both reservoirs, is typically located in a housing made of stainless steel, titanium, or any other strong corrosion resistant biocompatible material. The medication and carrier reservoirs are accessed through a medication access port and a carrier access port, respectively. The access ports are covered with a medication compound septum and a carrier compound septum, respectively. The carrier reservoir is larger, and thus holds a larger volume, than the medication reservoir. To reduce the size of the implantable infusion apparatus, the medication is highly concentrated to many times the dosage required. The concentrated medication is then diluted with the carrier, to the proper dose, before it is discharged to the patient.