The increasingly common scenario of an ageing population is related to a rise in the prevalence of problems associated with chronic conditions and comorbidities. Polypharmacy is frequent among this population, and it is a situation that can create medication management and adherence issues. This article introduces the features and functionalities of a voice assistant (Assistant on Health and Care Offline, ACHO) that aims to facilitate treatment adherence among elderly adults. Specifically adapted for its use in rural contexts, it does not require an Internet connection. Its development consisted of two stages: a first stage of problem diagnosis, in which the classic tools of ethnographic fieldwork were used, and a second stage of design implementing methodologies developed by Ambient Assisted Living (AAL) programmes. The main design characteristic of this new digital care system is that it is adapted to the needs of its end-users. It includes features such as voice customisation and the personal identification of medication, it can be connected to other digital devices, and information is introduced and supervised by healthcare professionals. These custom features introduce a safer medication administration procedure, improve supervision strategies, and increase patients’ trust in the prescription process.