Antidiuretic hormone concentrations following midazolam premedication.

Midazolam given orally the night before and on the morning of operation had a distinct subjective pre-operative sedative effect as compared with placebo. Patients receiving midazolam also experienced less apprehension and excitement before surgery, but in relation to quality of sleep, the difference between the two groups was not statistically significant. Antidiuretic hormone (ADH) concentrations were determined just before induction of anaesthesia and were significantly lower in the midazolam group (2.14 pg/ml, SD 0.96) than in the placebo group (3.07 pg/ml, SD 1.73). Our results show that midazolam is a useful sedative anxiolytic oral premedicant, which appears to prevent initiation of a stress reaction before induction of anaesthesia.