Abstract: An infusion pump can include a syringe receptacle, a retention mechanism, a drive mechanism, and a keyed lock. The retention mechanism can inhibit removal of the syringe from the receptacle when in an engaged state, and enable removal of the syringe when in a disengaged state. The drive mechanism can include a pusher to selectively couple to a thumb press of the syringe, a motor coupleable to the pusher, and a clutch to couple and decouple the motor to the pusher. The keyed lock can operate in coordination with the retention and drive mechanisms such that, if: the keyed lock is locked, the retention mechanism is in the engaged state, and the pusher is coupled to the thumb press of the syringe, then as long as the keyed lock remains locked, the retention mechanism is constrained to the engaged state and the clutch to the coupled state.