The invention concerns a secure device for dispensing a unitary dose (Mi) of an active substance in solid dosage form. Such a device comprises means for preventing the chamber containing the unitary doses from being filled a second time. It can further accommodate (51) a treatment unit and means for communication with the outside world. Such a device is particularly effective for combating the counterfeiting of drugs. It further makes it possible to detect non-compliance of a patient during a clinical trial or non-compliance of a patient suffering from a chronic disease.