title: Relationship between pain relief, reduction in pain-associated sleep interference, and overall impression of improvement in patients with postherpetic neuralgia treated with extended-release gabapentin.
abstract: BACKGROUND
  Postherpetic neuralgia (PHN) interferes with patients' quality of life, and disturbed sleep is a prevalent complaint. Pain-associated sleep interference in turn enhances pain and/or reduces pain tolerance. Therefore, reducing sleep interference by pain, in addition to pain control, may improve patient care. To address this notion, we characterized relationships among changes in pain intensity, sleep interference, and overall impression of improvement in PHN patients treated with gastroretentive gabapentin (G-GR).
  
  
  METHODS
  Patients with PHN (n = 556) received G-GR 1,800 mg once-daily in two phase 3 and one phase 4 study. Visual Analog Scale (VAS) and Brief Pain Inventory (BPI) were completed at baseline and the end of study. Patients' Global Impression of Change (PGIC) was completed at the end of study. Regression analyses examined relationships between VAS, BPI sleep interference by pain, and PGIC.
  
  
  RESULTS
  At the end of treatment, 53.7 and 63.2 % of patients reported a ≥ 30 % reduction in VAS and BPI pain-associated sleep interference (BPISI) respectively; 46.3 % reported feeling "Much" or "Very Much" improved on the PGIC. There were positive correlations between the percent reductions in VAS and BPISI; both correlated with PGIC improvements. Percent changes in VAS and BPISI were significant (p < 0.0001 and p = 0.0082, respectively), and were independent predictors of feeling "Much" or "Very Much" improved on the PGIC.
  
  
  CONCLUSIONS
  Reductions in pain intensity and in BPISI were correlated, and both also correlated with overall impression of improvement for patients with PHN treated with G-GR. Both pain relief and improvement BPISI independently predicted improvement in PGIC. For optimal patient care, clinicians should consider reducing the impact of pain on quality of sleep as well as overall pain reduction.
  
  
  BACKGROUND
  ClinicalTrials.gov numbers, NCT00335933 , NCT00636636 , NCT01426230.
authors.affiliation: Weill Cornell Medical College of Cornell University, New York, NY, USA. nem9015@med.cornell.edu.
authors.forename: Neel
authors.initials: N
authors.lastname: Mehta
authors.affiliation: Depomed, Inc., Newark, CA, USA.
authors.forename: Iwona
authors.initials: I
authors.lastname: Bucior
authors.affiliation: Depomed, Inc., Newark, CA, USA.
authors.forename: Shay
authors.initials: S
authors.lastname: Bujanover
authors.affiliation: St. Francis Hospital, Roslyn, NY, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Shah
authors.affiliation: Memorial Sloan Kettering Cancer Center, New York, NY, USA.
authors.forename: Amitabh
authors.initials: A
authors.lastname: Gulati
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000588:Amines / Q000627:therapeutic use*; D000700:Analgesics / Q000627:therapeutic use*; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use*; D003692:Delayed-Action Preparations / Q000627:therapeutic use; D005260:Female; D000077206:Gabapentin; D006801:Humans; D008297:Male; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000188:drug therapy*; D059408:Pain Management; D010147:Pain Measurement / Q000187:drug effects*; D015995:Prevalence; D011788:Quality of Life; D012890:Sleep / Q000187:drug effects*; D016896:Treatment Outcome; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use*
chemical_list: D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D003692:Delayed-Action Preparations; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin
keywords: Gabapentin; Gastroretentive; Neuropathic pain; Postherpetic neuralgia; Quality of life; Sleep