Oral premedication
The purpose of premedication and the best form have been frequent subjects of controversy among anaesthetists in the past few years. Anxiolysis is now accepted as the main purpose. The preferred route of administration is by mouth. The intention of this study was to examine whether clorazepate dipotassium has the same sedative-hypnotic and anxiolytic effects as i.m. premedication with promethazine, pethidine and atropine.
Methods: A total of 100 patients aged 20-65 years and due to undergo arthroscopy took part in this study. Patients in group I were given 1 mg flunitrazepam p.o. on the evening before the operation and the i.m. premedication described above. The premedication for group II consisted in clorazepate dipotassium, 50 mg on the evening before operation and 25 mg on the morning of the day of the operation. The sedative-hypnotic effects were measured on a four-point scale. The Erlangen anxiety scale (EAS) and a visual analogue scale (VAS) were used to evaluate the anxiolytic effects according to the patient's own and the observer's evaluation of mood. In addition to this, we measured amnesia, heart rate and blood pressure.
Results: Clorazepate dipotassium or flunitrazepam p.o. significantly reduces anxiety 1 h after administration as measured by the EAS (P < 0.05) on the evening before the operation. This result was not, however, confirmed by the VAS for self-assessment. Patients who received premedication with clorazepate dipotassium are less anxious on the morning of the operation than patients given flunitrazepam the evening before the operation (P < 0.05); this, however, does not correspond to the VAS results. There were no differences in the other parameters compared.
Discussion: Oral premedication with clorazepate dipotassium has the same sedative-hypnotic, anxiolytic and amnestic effects as i.m. premedication with promethazine, pethidine and atropine. The results of this study are better than those obtained by Tolksdorf et al., owing to the higher dosage used in our study (50 mg as against 20 mg). Tolksdorf et al. Failed to show any improvement on a placebo. Our results correspond to those of Drautz et al. who used 50 mg of clorazepate dipotassium on the evening before and 25 mg on the morning of the day of the operation.
The literature shows that benzodiazepines, in view of their anxiolytic, sedative, amnesic, muscle relaxant and anticonvulsive action, are the most important substances for premedication. Eminent workers regard anxiolysis as the most important aim of premedication. In the present clinical study, oral administration of the two different benzodiazepine derivatives, flunitrazepam (F) and chlorazepate dipotassium (CD) have been explored with a view to side effects, tolerance, quality of sleep during the night, anxiolytic effect and sedation. The study involved 108 women patients aged from 20 to 60 years (ASA class I or II), all scheduled to undergo gynecological surgery in general anesthesia. There were also 20 women who received no premedication. The three groups of patients were further divided into early (operation started before 10:30 a.m.) and late-operation (operation started after 10:30 a.m.) groups. The preoperative SaO2 saturation was decreased significantly by oral F, but it was always more than 95%. CD had little influence on the SaO2. Unwanted somatic symptoms were found a little more frequently in the group without any premedication. There were no signs of restricted tolerance for either of the test drugs. In the premedicated groups, pre- and postoperative anxiety decreased significantly.