An infusion device includes a housing with an interior chamber sized and configured to hold at least a flange and plunger of a syringe, a trigger held by the housing, and a lever in communication with the trigger and including an upwardly extending cam with a cam path having an upper end. The cam is in communication with the flange of the syringe. In response to actuation of the trigger to dispense fluid from the syringe, the upper end of the cam travels upward above the syringe and longitudinally toward a dispensing end of the syringe to linearly translate the plunger of the syringe in a first direction to dispense fluid from the syringe. To refill fluid into the syringe, the upper end of the cam travels downward and longitudinally away from the dispensing end of the syringe to linearly translate the plunger in a second direction to intake fluid.