An implantable flow regulator (22) for regulating flow of a drug along a drug delivery pathway (14) from a drug source to a treatment site within a subject includes a movable diversion member (24) and an actuator. The movable diversion member (24) is operably coupled to a delivery pathway (14). The actuator is actuatable to move the diversion member (24) between at least a first mode position where the diversion member (24) restricts flow through the delivery pathway (14) (i.e., delivery pathway is “closed”), and a second mode position where the diversion member (24) is position to allow flow through the delivery pathway (14) (i.e., delivery pathway is “open”). Supplying power to actuate the actuator moves the diversion member (24) from its normally biased first mode or “closed” position, which is also a failsafe position, toward its second mode or “open” position. In the “open” position, drug is supplied to target sites, typically from a drug supply reserve within the regulator.