Recurrence of respiratory depression following neurolept analgesia.

Fentanyl, though generally regarded as a short-acting narcotic analgesic, can give unexpected respiratory depression several hours after the last dose. This potentially very dangerous effect is explained in pharmacokinetic studies by a mobilisation of fentanyl from tissue stores. In this report we describe a patient who, following a Harrington correction for scoliosis done with neurolept analgesia, developed a severe respiratory depression 5 h after the last dose of fentanyl.