Flunitrazepam is a
benzodiazepine derivative whose
hypnotic effect predominates over the
sedative,
anxiolytic, muscle-relaxing and
anticonvulsant effects characteristic of
benzodiazepines. Thus, it is used as a night-time
hypnotic and in anaesthesiology: due to the pronounced
hypnotic effect it is not appropriate as a daytime
sedative. As a
hypnotic for
insomnia its effect is usually characterised by a very fast onset of action and quiet sleep without interruptions. On the morning after a
hypnotic dose some residual
psychomotor impairment does occur, which is comparable to that with usual doses of
nitrazepam or
flurazepam, but clinically apparent 'hangover' occurs infrequently. There is no pronounced cumulative effect with chronic use. In anaesthesiology it has proven to be useful as a
hypnotic on the night before operation, as an oral, intramuscular or intravenous
premedication, in induction and as a supplement to other anaesthetics. Its
sedative and amnesic properties can also be beneficial in
intensive care patients. Much of the usefulness of
flunitrazepam in anaesthesia relates to its synergistic effect with other anaesthetics, to its effective amnesic action and its acceptable effects on circulation and respiration. Possible drawbacks include a somewhat unusual course of induction (when used for this purpose) and an often prolonged recovery. Although the safe dosage range is wide with
flunitrazepam, its effective application both as a
hypnotic for
insomnia and in anaesthesiology is dependent upon use of the optimal dosage, and adequate knowledge of its pharmacokinetic properties.