[Remifentanyl. Indications in anesthesia].

Remifentanil is a new opioid in the fentanyl family. Developed and marketed by Glaxo Wellcome Inc., it was approved by the U.S. Food and Drug Administration in July 1996 and has been available for use in Spain since the end of 1997. Remifentanil is an analog of fentanyl (4-piperidyl anilide) with a methyl-ester group that allows the molecule to be hydrolyzed by esterases in plasma and tissues. Rapid onset and metabolism make it an easy drug to control for achieving the desired depth of anesthesia, although these aspects are also the drug's main drawbacks given that the anesthesiologist must plan and initiate postoperative analgesia before surgery ends. Rapid onset and potency also mean that the use of this drug for either postoperative analgesia or monitored sedation in awake state with spontaneous breathing needs further study to assess safety.