Described within is a device for monitoring the removal of articles contained in compartments of a standard blister package, in particular to assist a patient in following a prescribed programme of drugs. The compartments are covered with a rupturable cover. The removal of a drug out of the blister package is detected by photosensitive sensors located under the compartments, one per compartment. The device includes an opaque frame support comprising cavities which accommodate said standard blister package and covers the transparent faces of each compartment, which keeps light from the photosensitive sensors. Ambient light illuminates the photosensitive sensors when the cover of a compartment is torn and a drug removed from the compartment.