The newer, short-acting, nonbenzodiazepine hypnotic drugs, such as zolpidem, have been touted because of their apparently reduced daytime residual effects, compared with other insomnia drugs. Finnish scientists determined zolpidem and the benzodiazepine sleep agent temazepam, however, to be equal in their next-day residual effects on certain psychomotor activities.

A double-blind, randomized, placebo-controlled study, published in Sleep Medicine (November 2003), compared the earlymorning driving ability of women who had taken zolpidem or temazepam at 2 ^AM. Five and a half hours after dosing, there were no significant differences in almost all measures of the patients' driving ability, when compared with placebo.

Interestingly, the patients who were administered zolpidem had more difficulty maintaining proper lane position, compared with the temazepam and placebo groups. The study also highlighted the varied patient susceptibility to the effects of the drugs—an important consideration when evaluating individual treatment options for insomnia.