Assessing the residual effects of hypnotics.

The therapeutic efficacy of a hypnotic can not be judged solely on its ability to induce and improve sleep. Many of the older compounds produce residual effects the next morning, such as impaired performance, lack of concentration and day-time sedation. This "hangover" phenomena will only serve to make the problem worse rather than better. The patient's quality of life would suffer, and this is particularly apparent in older patients. Zopiclone and zolpidem, two novel compounds, are superior to the older benzodiazepines in that they do not impair performance on tests of cognition, reaction time and memory the day following drug ingestion. These drugs may prove to be more beneficial and safer in people with sleep disorders who want to carry on with everyday life.