Residue-free sodium phosphate tablets (OsmoPrep) versus Visicol for colon cleansing: a randomized, investigator-blinded trial.
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.
Wruble
Lawrence
L
Memphis Gastroenterology Group, Memphis, TN 38120, USA.
Demicco
Michael
M
Medoff
Jeffrey
J
Safdi
Alan
A
Bernstein
Jeffrey
J
Dalke
Douglas
D
Rose
Martin
M
Karlstadt
Robyn G
RG
Ettinger
Nancy
N
Zhang
Bing
B
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
D002400:Cathartics; D010710:Phosphates; D013607:Tablets; D002482:Cellulose; C109691:microcrystalline cellulose; C018279:sodium phosphate