A system for administering a medicament to spontaneously breathing patients, comprising: - i) a flexible catheter (101) adapted to reach the patient's retro-pharyngeal region, the catheter that includes at least a first channel (201) that is adapted to transport in the pharyngeal region of the patient a flow of liquid medicine and at least a second channel (203) adapted to transport in the pharyngeal region of the patient a flow of pressurized gas, - ii) first pumping means (103) connected to a first end of the at least first channel (201), adapted to create a low pressure that pushes the column of the liquid medicine towards the second end of the at least first channel (201)； - iii) second pumping means (105) connected to the first end of the at least second channel (203), adapted to create the flow of pressurized gas； so that when the liquid medicine column and the pressurized gas are in the pharyngeal cavity, the liquid column breaks into a plurality of particles which causes the atomized medicine to be released into the patient's lungs； - iv) a control unit (109) configured to control the pumping means； and characterized in that it also comprises: - v) a pressure sensor (107) connected to at least the first channel (201) to measure a value indicative of the presence in the pharyngeal cavity of the patient, such value is used by the control unit (109) to determine if the patient is in an inspiration or expiration phase and in which, in use, the first pumping means (103) is selectively activated by the control unit (109) only during the inspiration phase.Un sistema para administrar un medicamento a pacientes que respiran espontáneamente, que comprende: - i) un catéter flexible (101) adaptado para alcanzar la región retro-faríngea del paciente, el catéter que incluye al menos un primer canal (201) que está adaptado para transportar en la región faríngea del paciente un flujo de medicamento líquido y al menos un segundo canal (203) adaptado para transportar en la re
