[Evaluation of the histamine-liberating property of midazolam].

The variations of plasma histamine levels were studied in two groups of ten patients arriving in the operating room; the first group received midazolam, and the second a saline isotonic solution. The plasma histamine levels were compared, for each patient, to the histamine level measured the day before the operation. An histamine release was found as soon as the patient arrived in the operating room. No variation of the histamine level was found after the injection of midazolam.