An electrodiffusion pump includes a housing having an inlet, drug reservoir, and outlet. A diffusion membrane is disposed between the reservoir and outlet for diffusing the drug outwardly therethrough. Internal and external electrodes are disposed on opposite sides of the membrane. The electrodes are porous, and the external electrode is additionally perforate to expose a portion of the membrane at the outlet. The electrodes are electrically powered for driving drug ions through the membrane under electrophoresis to complement diffusion thereof.