title: Quantitative sensory testing predicts pregabalin efficacy in painful chronic pancreatitis.
abstract: BACKGROUND
  A major problem in pain medicine is the lack of knowledge about which treatment suits a specific patient. We tested the ability of quantitative sensory testing to predict the analgesic effect of pregabalin and placebo in patients with chronic pancreatitis.
  
  
  METHODS
  Sixty-four patients with painful chronic pancreatitis received pregabalin (150-300 mg BID) or matching placebo for three consecutive weeks. Analgesic effect was documented in a pain diary based on a visual analogue scale. Responders were defined as patients with a reduction in clinical pain score of 30% or more after three weeks of study treatment compared to baseline recordings. Prior to study medication, pain thresholds to electric skin and pressure stimulation were measured in dermatomes T10 (pancreatic area) and C5 (control area). To eliminate inter-subject differences in absolute pain thresholds an index of sensitivity between stimulation areas was determined (ratio of pain detection thresholds in pancreatic versus control area, ePDT ratio). Pain modulation was recorded by a conditioned pain modulation paradigm. A support vector machine was used to screen sensory parameters for their predictive power of pregabalin efficacy.
  
  
  RESULTS
  The pregabalin responders group was hypersensitive to electric tetanic stimulation of the pancreatic area (ePDT ratio 1.2 (0.9-1.3)) compared to non-responders group (ePDT ratio: 1.6 (1.5-2.0)) (P = 0.001). The electrical pain detection ratio was predictive for pregabalin effect with a classification accuracy of 83.9% (P = 0.007). The corresponding sensitivity was 87.5% and specificity was 80.0%. No other parameters were predictive of pregabalin or placebo efficacy.
  
  
  CONCLUSIONS
  The present study provides first evidence that quantitative sensory testing predicts the analgesic effect of pregabalin in patients with painful chronic pancreatitis. The method can be used to tailor pain medication based on patient's individual sensory profile and thus comprises a significant step towards personalized pain medicine.
authors.affiliation: Mech-Sense, Department of Gastroenterology, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark.
authors.forename: Søren S
authors.initials: SS
authors.lastname: Olesen
authors.forename: Carina
authors.initials: C
authors.lastname: Graversen
authors.forename: Stefan A W
authors.initials: SA
authors.lastname: Bouwense
authors.forename: Harry
authors.initials: H
authors.lastname: van Goor
authors.forename: Oliver H G
authors.initials: OH
authors.lastname: Wilder-Smith
authors.forename: Asbjørn M
authors.initials: AM
authors.lastname: Drewes
mesh_terms: D000328:Adult; D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology* / Q000523:psychology; D050500:Pancreatitis, Chronic / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D010919:Placebos; D057285:Precision Medicine; D000069583:Pregabalin; D011312:Pressure; D012680:Sensitivity and Specificity; D060388:Support Vector Machine; D016896:Treatment Outcome; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000700:Analgesics; D010919:Placebos; D000069583:Pregabalin; D005680:gamma-Aminobutyric Acid