Hypnotics and transient insomnia.

An hypnotic should be used only when there is evidence of sleep disturbance. The wide range of sleep disorders (e.g. delayed sleep onset or problems of sleep maintenance) and the added complication that the patient may be involved subsequently in skilled work demand that the pharmacokinetics of various hypnotics must be understood before the correct hypnotic can be chosen. Impaired performance is more severe and persists far longer with compounds that are slowly eliminated and with the use of higher doses. The particular situations of aircrew and mountaineers have been studied in detail. Caution must be exercised in the management of aircrew coping with irregularity of rest and work. Temazepam has been used for aircrew for over 10 years and the absence of adverse effects ensures that it remains the recommended hypnotic in this area of medical practice. The relationship of insomnia with the hypoxic environment is undetermined. To investigate this, sleep was studied in six individuals during an expedition to the Himalayas. At altitude, temazepam led to less wakefulness and to drowsy sleep--there were no prolonged sleep latencies.