title: A double-blind comparative study of zolpidem versus zopiclone in the treatment of chronic primary insomnia.
abstract: Zolpidem (10 mg/day) and zopiclone (7.5 mg/day), administered at night, were compared in a 14-day, double-blind, equivalence trial on 479 chronic primary insomniacs (zolpidem, 231; zopiclone, 248) throughout Japan, with a 1-week follow-up to assess rebound. The primary endpoint was the investigators' rating of global improvement of sleep disorders. A total of 32 patients in the zolpidem group (13.9%) and 45 patients in the zopiclone group (18.1%) withdrew from the study before the end of the treatment. In the zolpidem group, 67.9% (142/209) of patients were rated at least 'moderately improved' versus 61.6% (135/219) with zopiclone, zolpidem being at least as effective as zopiclone (90% confidence interval: -1.7, 14.3). With zolpidem, sleep onset latency improved in significantly more patients (85.8% versus 77.5%) and significantly fewer patients showed aggravated sleep onset latency relative to baseline at follow-up (4.5% versus 15.4%). Significantly fewer patients receiving zolpidem experienced drug-related adverse events (31.3% versus 45.3%), with bitter taste representing 5.8% (six of 104) of such complaints with zolpidem compared with 39.9% (69/173) with zopiclone. In conclusion, zolpidem was at least as effective as zopiclone, showed significantly less rebound on discontinuation and was better tolerated.
authors.affiliation: Department of Psychosomatic Medicine, Toho University Medical School, Omori Hospital, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tsutsui
mesh_terms: D000328:Adult; D053961:Azabicyclo Compounds; D002908:Chronic Disease; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011725:Pyridines / Q000009:adverse effects / Q000627:therapeutic use*; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*; D000077334:Zolpidem
chemical_list: D053961:Azabicyclo Compounds; D006993:Hypnotics and Sedatives; D010879:Piperazines; D011725:Pyridines; C515050:zopiclone; D000077334:Zolpidem