Dolor agudo o episodico por cáncer

introduction: from the concept introduced by the international association for the study and treatment of pain, the terms acute, subacute, chronic and intermittent pain are considered and key in the course of pain in a cancer patient, as well as the elements related to pain pathophysiology. objectives: to identify the incidence and prevalence of episodical pain know as "breakthrough pain", the definitions of other authors, the clinical features and its control using opioids. development: it is refer to the pathophysiological features of cancer pain and the causes that could originate it in its interrelation with acute pain due to cancer. it is emphasized the role played by the osteoclastic and osteoblastic activity and the allogenic substances produced from the tumor stroma causing the incidental pain. authors analyzed the definitions of "breakthrough pain" mentioned by some authors. the use of opioids in the basal control of cancer pain and the usefulness of the new opioids of fast action are examined are the ideal treatment of episodical pain due to cancer how we define in spanish language to the term used in english language during years. conclusions: it is essential and important the appropriate use of the fentanyl formulas with a good titration of dose to be use.