End-of-use and end-of-life medicines waste management has been a challenge for public and private managers in different countries. Reverse logistics is a waste management strategy whose application to public pharmaceutical care processes faces legal restrictions and incertitude. Nevertheless, reverse logistics of end-of-use and end-of-life medicines may be both a saving and an environmental strategy in developing countries that manage health under limited resources. How to overcome restrictions to reverse logistics mainly in the context of primary health level? This study aims to investigate the most relevant critical factors for implementing medicine waste management in pharmaceutical care process. The unit analysis is the primary health level process in a developing country capital. Considering the characteristics of the issue at hand, it was designed a qualitative study. Data was collected through semi-structured interviews. The interviewees were key individuals who work directly with the process-from administering medicine to patients to managing waste at the end of the medicine's lifespan or after its use. Results indicated that despite reverse logistics arising from end users is legally forbidden, another type of reverse flow emerged from process analysis. The reverse flow, named reassignment flow, consists of still useful end-of-use medicines exchanged among the 10 government-ran pharmacies and over 140 health centers, where healthcare professionals administer and offer guidance on how to use them correctly. Another result was the identification of the most critical factors in implementing reverse logistics strategies in the public management context. The factors mentioned included aspects pertaining to management, information technology, infrastructure, and government, but they differ from the private context management, in which decision-makers has more freedom. Due to the barriers named by interviewees, the political barriers and complexity of primary health system, results of this investigation point to (i) reinforcing the reassignment flows inside pharmaceutical care logistics cycle, for saving purposes, and (ii) further development of a specific management unit to perform reverse logistics of end-of-use medicines arising from consumers, for environmental purposes. In times of shortage or resources caused by the COVID-19 pandemic, to know the critical factors is a step necessary in overcoming the current restrictions in direction of a well-succeeded medicines reverse logistics, either of reassignment or from final consumers. These results clarify the literature on end-of-use and end-of-life medicines reverse logistics. It also provides managers of 5000 municipalities in the country a perspective on the most relevant critical factors involved in their decision-making process, concerning the reuse of end-of-use medicines or the adequate disposal of end-of-life medicines in the environment.
