[The preoperative medication: background and specific indications for the selection of the drugs].

Prior to an operation, patients experience a high degree of stress and internal tension. Preoperative drug administration (premedication) is intended to reduce these stresses through anxiolytic and sedative effects. On account of their good anxiolytic actions, there excellent tolerability and only few side effects benzodiazepines are most frequently used for this purpose. To support the induction and continuation of sleep, premedication is usually initiated in the evening before operation with the administration of a benzodiazepine with middle- or long-term activity. The standard drug for the day of operation is the short-acting benzodiazepine midazolam, under the action of which the patient may be transferred to the operation room in a drowsy and calm state. The onset of action of drugs applied as preoperative medication is delayed. Thus, it is of major importance that the premedication be administered at the appropriate time point so that the patient really is shielded fro preoperative stress at the time of the drug's optimal effect. Although midazolam is not the ideal substance for all situations where an anxiolytic premedication is needed, with the exception of a few special indications, no decisive advantages over other drugs have been demonstrated in comparative trials.