Isolation plugs may be installed in a wellbore flow control device to temporarily close a flow path therethrough. The isolation plugs may be installed in threaded openings often provided to for access to nozzles or other flow restrictors in the flow control devices. The isolation plugs may initially be locked in a closed configuration while being run in hole and may be unlocked in response to the application of a predetermined activation pressure. Once unlocked, the isolation plug may not immediately move to an open configuration but may continue holding pressure to permit circulation and washdown operations to be conducted. The activation pressure may be reduced to a second predetermined threshold to lock the isolation plug in the open configuration wherein flow is permitted through the flow control device.