Electrotransport drug delivery devices, system and methods of using configured to determine if a current is present between the anode and cathode when drug is not intended to be delivered by the device. These devices/systems may include an off-current module to determine that any current (e.g., which may be inferred by measuring potential difference between the anode and cathode of the device) flowing between the anode and cathode is below a threshold value when the device is not supposed to be delivering drug, thereby preventing unintended delivery of drug and/or alerting a user that unintended delivery of drug may occur.