title: Residue-free sodium phosphate tablets (OsmoPrep) versus Visicol for colon cleansing: a randomized, investigator-blinded trial.
abstract: BACKGROUND
  The bowel purgative Visicol contains microcrystalline cellulose (MCC) residue, which may impair full visibility during a colonoscopy. An MCC residue-free sodium phosphate (RF-NaP; OsmoPrep) tablet was developed.
  
  
  OBJECTIVE
  To investigate appropriate RF-NaP dosing.
  
  
  METHODS
  Phase 2, randomized, investigator-blinded study.
  
  
  METHODS
  Six research centers in the United States.
  
  
  METHODS
  Patients undergoing a colonoscopy received Visicol (n = 34) or 1 of 6 RF-NaP regimens administered as either split (S) dosing (the evening before and the day of colonoscopy) or evening-only (E) dosing. Dosing regimens for RF-NaP were 40 tablets S, 3 every 15 minutes (n = 33); 40 tablets S, 4 every 15 minutes (n = 34); 32 tablets E, 4 every 15 minutes (n = 34); 32 tablets S, 4 every 15 minutes (n = 36); 28 tablets E, 4 every 15 minutes (n = 34); 28 tablets S, 4 every 15 minutes (n = 34). Visicol was administered as 40 tablets S, 3 every 15 minutes.
  
  
  METHODS
  Overall colon cleansing (OCC) was assessed by a physician questionnaire (4-point scale, based on colonic contents). An OCC rating of "excellent" or "good" was considered a response. Safety measures were also monitored.
  
  
  RESULTS
  Split dosing with RF-NaP was associated with high OCC and achieved response rates of 90%, 97%, and 100% for 28, 32, and 40 tablets, respectively, compared with 86% for Visicol. In addition, RF-NaP evening-only regimen response rates were 90% (32 tablets) and 72% (28 tablets). Transient shifts in electrolyte levels were reduced, and GI adverse events were less common with lower RF-NaP dose regimens.
  
  
  CONCLUSIONS
  Administration of RF-NaP retains the benefits of a tablet purgative but eliminates MCC issues. Split dosing and 32-tablet evening-only dosing of RF-NaP tablets were efficacious and well tolerated, and split dosing of RF-NaP tablets is recommended.
authors.affiliation: Memphis Gastroenterology Group, Memphis, TN 38120, USA.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Wruble
authors.forename: Michael
authors.initials: M
authors.lastname: Demicco
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Medoff
authors.forename: Alan
authors.initials: A
authors.lastname: Safdi
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bernstein
authors.forename: Douglas
authors.initials: D
authors.lastname: Dalke
authors.forename: Martin
authors.initials: M
authors.lastname: Rose
authors.forename: Robyn G
authors.initials: RG
authors.lastname: Karlstadt
authors.forename: Nancy
authors.initials: N
authors.lastname: Ettinger
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002400:Cathartics / Q000627:therapeutic use*; D002482:Cellulose; D003113:Colonoscopy; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D010710:Phosphates / Q000008:administration & dosage / Q000627:therapeutic use*; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D013607:Tablets
chemical_list: D002400:Cathartics; D010710:Phosphates; D013607:Tablets; D002482:Cellulose; C109691:microcrystalline cellulose; C018279:sodium phosphate