[Effect and side effects of oral morphine, lormetazepam and placebos as premedication]

In 60 patients undergoing a curettage in thiopentone induced inhalation anaesthesia with enflurane and N2O/O2 = 2:1, the effects of oral premedication (2 h before anaesthesia) with 30 mg morphine (MST 30) (n = 21), 1 mg lormetazepam (Noctamid) (n = 19) and placebo (n = 21) on psychological (anxiety, depression and asthenia), physiological (blood pressure, heart and respiratory rate) and pain parameters (visual analogue scale, analgesic consumption) were investigated. The study design was single blind, randomized. Before premedication the three groups did not differ in one parameter and so were comparable. MST 30 had a significantly better anxiolytic, Lormetazepam a significantly better antidepressive effect than the compared substance. There were no differences in blood pressure and heart rate. In contrast to lormetazepam and placebo after MST 30 there was no increase in the respiratory rate which can be explained by the anxiolytic stress reducing effect. There was no difference in peri- and intraoperative pain parameters, probably due to the type of surgery. Nausea and vomiting occurred more frequently after MST 30, but there was no significance. A higher rate was probably prevented by the application of transdermal scopolamine the day before surgery. The indication of analgesics (opiates) for premedication is discussed taking the controversy into account. The results of this study show that oral morphine (MST 30) has an anxiolytic effect, one of the most important effects a premedication should have. Further studies should investigate in which types of surgery the analgesic effect of MST 30 is peri- and intraoperatively relevant, so that advantages compared to e.g. Flunitrazepam, Midazolam or Lormetazepam in a higher dosage could be expected.