Direct Current (DC) interruption poses particular challenges to protection devices and circuit breakers. While both at DC transmission level and in the low voltage (LV) range efficient and cost-effective solutions are nowadays available, at medium voltage (MV) distribution level a clear preferred technology is not yet identified. In this paper we analyze the reasons for this and review some of the technologies under development for current interruption in Medium Voltage (MV) DC distribution systems. The comparison is carried out in terms of speed of operation, voltage scalability and technical readiness level and includes mechanical, solid-state and hybrid (combination of mechanical and solid state switches) concepts. Examples of test results from lab demonstrators and prototypes are reported, together with an outline of the next development steps.