Comparison of continuous versus intermittent administration of zolpidem in chronic insomniacs: a double-blind, randomized pilot study.

The subjective efficacy and safety of intermittent administration of a hypnotic for insomnia was assessed, since such a regime may provide a potential means of reducing the risk of habituation and dependence. A total of 160 adult patients (mean 45 years) with chronic insomnia were treated for 2 weeks with zolpidem, 10 mg, either continuously or intermittently (five nights zolpidem, two consecutive nights placebo per week) in this multicentre, out-patient, pilot study. At the end of the 2-week treatment, patients subjectively estimated their nightly total sleep time as 6.96 +/- 1.19 h (from 6.07 +/- 1.25 h at baseline) and 6.94 +/- 1.30 h (from 5.72 +/- 1.46 h) after the continuous and intermittent treatments, respectively. Patients' reports did not indicate any differences between the two groups in global evaluation of impairment, sleep quality, or the incidence of adverse events. These results suggest that the efficacy and safety of zolpidem, 10 mg, are comparable whether the drug is administered every night or intermittently. Further studies with a broader well-defined patient base, are needed to confirm these data.