Study designs of evaluations included in the review
Case reports were eligible for inclusion. Clinical studies were excluded.
Specific interventions included in the review
Although explicit inclusion criteria were not reported for the interventions, cases of zolpidem and zopiclone were eligible for inclusion. The doses of zolpidem and zopiclone varied across the included cases, and in some instances both agents were given.
Participants included in the review
Explicit inclusion criteria were not reported. The majority of the patients had a history of former drug or alcohol abuse and/or other psychiatric conditions. The ages ranged from 16 to 75 years and similar numbers of cases were reported for men and women.
Outcomes assessed in the review
Explicit inclusion criteria were not reported. The authors stated that attention was paid to data reporting the use of higher than recommended doses, intake for other than the recommended indication (including intake of the hypnotic during daytime), and measures of dependence such as loss of efficacy due to tolerance, dose increase over time, and the occurrence of withdrawal symptoms following cessation of drug intake.
How were decisions on the relevance of primary studies made?
Two reviewers assessed potentially relevant citations for inclusion.