NEW DRUG REVIEW A Novel PEG 3350 Formulation David M. Kastenberg, MD
Clinical Assistant Professor of Medicine Division of Gastroenterology and Hepatology Thomas Jefferson University In August of 2006, the US Food and Drug Administration approved a novel formulation of polyethelene glycol (PEG) 3350 for bowel preparation and cleansing before colonoscopy in patients age 18 and over. MoviPrep (Salix Pharmaceuticals) is composed of PEG 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, and ascorbic acid in a 2-liter liquid solution. The inclusion of ascorbic acid and sodium ascorbate, which act as a laxative in high concentrations, is unique to this formulation and adds to the efficacy of the standard PEG solution. MoviPrep was originally tested in a German noninferiority study that compared it to the European market PEG solution, Klean-Prep (Helix BioPharma). Two dosing regimens of MoviPrep were examined. The first administered the full 2-liter preparation the night before the procedure with an accompanying liter of clear liquid. In the other regimen, the first liter was given the night before and the second liter on the morning of the procedure, each with 500 mL clear liquid. Both regimens were shown to be effective, but patient satisfaction was greater with MoviPrep. Safety results were similar for MoviPrep and Klean-Prep and rates of adverse events acceptable for all regimens. Because the scoring system utilized in Germany was not standard for US studies, our group conducted a follow-up that blindly reviewed 100 of the recorded German colonoscopies and graded them based on a simplified scale that has been validated in the United States. Results of our study were presented at the 2006 American College of Gastroenterology meeting in Las Vegas and showed that scores for the European scoring system and the US system were equivalent, with nearly identical results in terms of efficacy. Liquid PEG formulations provide an alternative to sodium phosphate bowel preparations, which cannot be used in patients with decompensated liver disease,
ascites, advanced heart disease, any kidney insufficiency, or baseline electrolyte abnormalities. The majority of the currently available PEG solutions are 4-liter formulations. Generally, these largevolume preparations are not as well tolerated as sodium phosphate purgatives. There is one other 2-liter preparation (HalfLytely, Braintree Labs), which has proven very popular because the reduced volume of PEG solution improves patient tolerability. However, HalfLytely also requires the co-administration of four bisacodyl laxative tablets, taken 5 hours before the preparation, which itself is administered the evening before the procedure. Bisacodyl has been associated with cramping, and midday administration of this additional agent may detract from the preparation’s overall tolerability and convenience of administration. MoviPrep requires no additional laxative medication and offers the flexibility of completing the prep the night before, or splitting the dose between the prior evening and the morning of colonoscopy. Most studies of bowel preparation, with either PEG or sodium phosphate formulations, show improved efficacy when part of the dose is taken the morning of the procedure. It should be noted that all bowel preparations cause some level of dehydration. My recommendation is that patients take only clear liquids the day before, preferably containing a combination of sugar and electrolytes. I recently revised our colonoscopy instructions at Thomas Jefferson University to encourage patients on the afternoon before the prep to take a liter of fluids in addition to their normal intake of clear liquid. Patients often misunderstand the benefit of additional clear liquids, thinking that the less they take, the cleaner their colon will be. In reality additional clear liquids improve the overall safety of the procedure, regardless of the preparation method. Suggested Reading Kastenberg D, Lottes SR, Forbes WP. An effective 2L polyethelene glycol (PEG) electrolyte lavage solution for bowel cleansing. Am J Gastroenterol. 2006;101 (9 suppl 1):S532.
Gastroenterology & Hepatology Volume 2, Issue 11 November 2006
827
Clinical Assistant Professor of Medicine Division of Gastroenterology and Hepatology Thomas Jefferson University In August of 2006, the US Food and Drug Administration approved a novel formulation of polyethelene glycol (PEG) 3350 for bowel preparation and cleansing before colonoscopy in patients age 18 and over. MoviPrep (Salix Pharmaceuticals) is composed of PEG 3350, sodium sulfate, sodium chloride, potassium chloride, sodium ascorbate, and ascorbic acid in a 2-liter liquid solution. The inclusion of ascorbic acid and sodium ascorbate, which act as a laxative in high concentrations, is unique to this formulation and adds to the efficacy of the standard PEG solution. MoviPrep was originally tested in a German noninferiority study that compared it to the European market PEG solution, Klean-Prep (Helix BioPharma). Two dosing regimens of MoviPrep were examined. The first administered the full 2-liter preparation the night before the procedure with an accompanying liter of clear liquid. In the other regimen, the first liter was given the night before and the second liter on the morning of the procedure, each with 500 mL clear liquid. Both regimens were shown to be effective, but patient satisfaction was greater with MoviPrep. Safety results were similar for MoviPrep and Klean-Prep and rates of adverse events acceptable for all regimens. Because the scoring system utilized in Germany was not standard for US studies, our group conducted a follow-up that blindly reviewed 100 of the recorded German colonoscopies and graded them based on a simplified scale that has been validated in the United States. Results of our study were presented at the 2006 American College of Gastroenterology meeting in Las Vegas and showed that scores for the European scoring system and the US system were equivalent, with nearly identical results in terms of efficacy. Liquid PEG formulations provide an alternative to sodium phosphate bowel preparations, which cannot be used in patients with decompensated liver disease,
ascites, advanced heart disease, any kidney insufficiency, or baseline electrolyte abnormalities. The majority of the currently available PEG solutions are 4-liter formulations. Generally, these largevolume preparations are not as well tolerated as sodium phosphate purgatives. There is one other 2-liter preparation (HalfLytely, Braintree Labs), which has proven very popular because the reduced volume of PEG solution improves patient tolerability. However, HalfLytely also requires the co-administration of four bisacodyl laxative tablets, taken 5 hours before the preparation, which itself is administered the evening before the procedure. Bisacodyl has been associated with cramping, and midday administration of this additional agent may detract from the preparation’s overall tolerability and convenience of administration. MoviPrep requires no additional laxative medication and offers the flexibility of completing the prep the night before, or splitting the dose between the prior evening and the morning of colonoscopy. Most studies of bowel preparation, with either PEG or sodium phosphate formulations, show improved efficacy when part of the dose is taken the morning of the procedure. It should be noted that all bowel preparations cause some level of dehydration. My recommendation is that patients take only clear liquids the day before, preferably containing a combination of sugar and electrolytes. I recently revised our colonoscopy instructions at Thomas Jefferson University to encourage patients on the afternoon before the prep to take a liter of fluids in addition to their normal intake of clear liquid. Patients often misunderstand the benefit of additional clear liquids, thinking that the less they take, the cleaner their colon will be. In reality additional clear liquids improve the overall safety of the procedure, regardless of the preparation method. Suggested Reading Kastenberg D, Lottes SR, Forbes WP. An effective 2L polyethelene glycol (PEG) electrolyte lavage solution for bowel cleansing. Am J Gastroenterol. 2006;101 (9 suppl 1):S532.
Gastroenterology & Hepatology Volume 2, Issue 11 November 2006
827
