title: Long-term efficacy and safety of zolpidem extended-release 12.5 mg, administered 3 to 7 nights per week for 24 weeks, in patients with chronic primary insomnia: a 6-month, randomized, double-blind, placebo-controlled, parallel-group, multicenter study.
abstract: OBJECTIVE
  To evaluate long-term efficacy and safety of zolpidem extended-release 3 to 7 nights/week for chronic primary insomnia.
  
  
  METHODS
  Multicenter, 25-week, phase IIIb, randomized, double-blind, placebo-controlled, parallel-group.
  
  
  METHODS
  Outpatient; visits every 4 weeks.
  
  
  METHODS
  Aged 18 to 64 years; DSM-IV criteria for chronic primary insomnia; > or =3 months of difficulty initiating or maintaining sleep or experiencing nonrestorative sleep.
  
  
  METHODS
  Single-dose zolpidem extended-release 12.5 mg (n = 669) or placebo (n = 349), self-administered from a minimum of 3 nights/week to a maximum of 7 nights/week.
  
  
  RESULTS
  Patient's Global Impression (PGI) and Clinical Global Impression-Improvement (CGI-I) were assessed every 4 weeks up to week 24. Patient Morning Questionnaire (PMQ), recorded daily, assessed subjective sleep measures-sleep onset latency (SOL), total sleep time (TST), number of awakenings (NAW), wake time after sleep onset (WASO), and quality of sleep (QOS)-and next-day functioning. At week 12, PGI, Item 1 (aid to sleep), the primary endpoint, was scored as favorable (i.e., "helped me sleep") by 89.8% of zolpidem patients vs. 51.4% of placebo patients (P < 0.0001, based on rank score) and at week 24 by 92.3% of zolpidem extended-release patients vs. 59.7% of placebo patients. Zolpidem extended-release also was statistically significantly superior to placebo at every time point for PGI (Items 1-4) and CGI-I (P < 0.0001, rank score), TST, WASO, QOS (P < 0.0001), and SOL (P < or = 0.0014); NAW (Months 2-6; P < 0.0001). Sustained improvement (P < 0.0001, all time points) was observed in morning sleepiness and ability to concentrate (P = 0.0014, month 6) with zolpidem extended-release compared with placebo. Most frequent adverse events for zolpidem extended-release were headache, anxiety and somnolence. No rebound effect was observed during the first 3 nights of discontinuation.
  
  
  CONCLUSIONS
  These findings establish the efficacy of 3 to 7 nights per week dosing of zolpidem extended-release 12.5 mg for up to 6 months. Treatment provided sustained and significant improvements in sleep onset and maintenance and also improved next-day concentration and morning sleepiness.
authors.affiliation: Duke University Medical Center, Durham, NC 27710, USA. kryst001@mc.duke.edu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krystal
authors.forename: Milton
authors.initials: M
authors.lastname: Erman
authors.forename: Gary K
authors.initials: GK
authors.lastname: Zammit
authors.forename: C
authors.initials: C
authors.lastname: Soubrane
authors.forename: Thomas
authors.initials: T
authors.lastname: Roth
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002908:Chronic Disease; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004361:Drug Tolerance; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011725:Pyridines / Q000008:administration & dosage* / Q000009:adverse effects; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*; D011795:Surveys and Questionnaires; D000077334:Zolpidem
chemical_list: D003692:Delayed-Action Preparations; D006993:Hypnotics and Sedatives; D011725:Pyridines; D000077334:Zolpidem