Polyethylene Glycol
Indications: Constipation
DESCRIPTION:
A white powder for reconstitution. MiraLax is a synthetic polyglycol having an average molecular weight of 3350. The actual molecular weight is not less than 90.0% and not greater than 110.0% of the nominal value. The chemical formula is HO(C3H4O)nH in which n represents the average number of oxyethylene groups. Below 55Β°C it is a free flowing white powder freely soluble in water.
Polyethylene glycol is an osmotic agent for the treatment of constipation.
CLINICAL PHARMACOLOGY:
Macrogols are inert polymers of ethylene glycol which sequester fluid in the bowel; giving fluid with macrogols may reduce the dehydrating effect sometimes seen with osmotic laxatives.
In children with faecal impaction, an oral preparation containing macrogols is used to clear faecal mass and to establish and maintain soft well-formed stools.
Cautions
pregnancy; breast-feeding ; discontinue if symptoms of fluid and electrolyte disturbance
Contra-indications
intestinal perforation or obstruction, paralytic ileus, severe inflammatory conditions of the intestinal tract (such as Crohn's disease, ulcerative colitis, and toxic megacolon), see also preparations below
Polyethylene glycol is an osmotic agent which causes water to be retained with the stool.
Essentially, complete reovery of polyethylene glycol was shown in normal subjects without constipation. Attempts at recovery of polyethylene glycol in constipated patients resulted in incomplete and highly variable recovery. In vitro study showed indirectly that polyethylene glycol was not fermented into hydrogen or methane by the colonic microflora in human feces. Polyethylene glycol appears to have no effect on the active absorption or secretion of glucose or electrolytes. There is no evidence of tachyphylaxis.
CLINICAL STUDIES:
In one study, patients with less than 3 bowel movements per week were randomized to polyethylene glycol, 17 grams, or placebo for 14 days. An increase in bowel movement frequency was observed for both treatment groups during the first week of treatment.
In another study, patients with 3 bowel movements or less per week and/or less than 300 grams of stool per week were randomized to 2 dose levels of polyethylene glycol or placebo for 10 days each. Success was defined by an increase in both bowel movement frequency and daily stool weight. For both parameters, superiority of the 17 gram dose of polyethylene glycol over placebo was demonstrated.
INDICATIONS AND USAGE:
For the treatment of occasional constipation. This product should be used for 2 weeks or less or as directed by a physician.
CONTRAINDICATIONS:
Polyethylene glycol is contraindicated in patients with known or suspected bowel obstruction and patients known to be allertic to polyethylene glycol.
WARNINGS:
Patients with symptoms suggestive of bowel obstruction (nausea, vomiting, abdominal pain, or distention) should be evaluated to rule out this condition before initiating polyethylene glycol therapy.
PRECAUTIONS:
General: Patients presenting with complaints of constipation should have a thorough medical history and physical examination to detect associated metabolic, endocrine and neurogenic conditions, and medications. A diagnostic evaluation should include a structural examination of the colon. Patients should be educated about good defecatory and eating habits (such as high fiber diets) and lifestyle changes (adequate dietary fiber and fluid intake, regular exercise) which may produce more regular bowel habits.
Polyethylene glycol should be administered dissolved in approximately 8 ounces of water.
Information for the Patient: Polyethylene glycol softens the stool and increases the frequency of bowel movements by retaining water in the stool. It should always be taken by mouth after being dissolved in 8 ounces of water. Should unusual cramps, bloating, or diarrhea occur, consult your physician.
Two to 4 days may be required to produce a bowel movement. This product should be used for 2 weeks or less or as directed by a physician. Prolonged, frequent, or excessive use of polyethylene glycol may result in electrolyte imbalance and dependence on laxatives.
Laboratory Tests: No clinically significant effects on laboratory tests have been demonstrated.
Carcinogenesis, Mutagenesis, and Impairment of Fertility: Long term carcinogenicity studies, genetic toxicity studies, and reproductive toxicity studies in animals have not been performed with polyethylene glycol.
Pregnancy Category C: Animal reproductive studies have not been performed with polyethylene glycol. It is also not known whether polyethylene glycol can cause fetal harm when administered to a pregnant woman, or can effect reproductive capacity. Polyethylene glycol should only be administered to a pregnant woman if clearly needed.
Pediatric Use: Safety and effectiveness in pediatric patients has not been established.
Geriatric Use: There is no evidence for special considerations when polyethylene glycol is administered to elderly patients.
In geriatric nursing home patients a higher incidence of diarrhea occurred at the recommended 17 gram dose. If diarrhea occurs, polyethylene glycol should be discontinued.
DRUG INTERACTIONS:
No specific drug interactions have been demonstrated.
ADVERSE REACTIONS:
Nausea, abdominal bloating, cramping, and flatulence may occur. High doses may produce diarrhea and excessive stool frequency, particularly in elderly nursing home patients.
Patients taking other medications containing polyethylene glycol have occasionally developed urticaria suggestive of an allergic reaction.
OVERDOSAGE:
There have been no reports of accidental overdosage. In the event of overdosage diarrhea would be the expected major event. If an overdose of drug occurred without concomitant ingestion of fluid, dehydration due to diarrhea may result. Medication should be terminated and free water administered. The oral LD50 is >50 gm/kg in mice, rats, and rabbits.
DOSAGE AND ADMINISTRATION:
The usual dose is 17 grams (about 1 heaping tablespoon) of powder per day (or as directed by physician) in 8 ounces of water. Each bottle of MiraLax is supplied with a measuring cap marked to contain 17 grams of laxative powder when filled to the indicated line.
Two to 4 days (48 to 96 hours) may be required to produce a bowel movement.
PATIENT PACKAGE INSERT:
Polyethylene glycol is a prescription only laxative which has been prescribed by your doctor to treat constipation. This product should only be used by the person for whom it was prescribed.
How to Take: The dose is 17 grams each day or as directed by physician. It should always be taken by mouth. Measure the dose using the measuring cap (or use one heaping tablespoon of powder), stir and dissolve in a glass (8 oz.) of water. Taking more than the prescribed dose may cause loss of fluid due to severe diarrhea.
How Will it Work: Polyethylene glycol softens the stool and increases the frequency of bowel movements by retaining water in the stool. Your first bowel movement will usually happen in 2 to 4 days, although results may vary for individual patients.
How Long Should I Take it?: Polyethylene glycol achieves its best results when used between 1 and 2 weeks. You may discontinue taking the drug after you have had several satisfactory bowel movements. Should unusual cramps, bloating, or diarrhea occur, consult your physician. Polyethylene glycol is intended for up to a 2 week course of therapy. You should not use for a longer time unless directed by your doctor.
Next Steps: After successfully completing the polyethylene glycol therapy (usually between 1 and 2 weeks) please discuss with your doctor lifestyle changes which may produce more regular bowel habits (adequate dietary and fluid intake, regular exercise).
Who Should NOT Take Polyethylene Glycol: Polyethylene glycol should not be used by children. It should not be used by pregnant women unless prescribed by a physician.
Side Effects/Drug Reactions: Occasionally, polyethylene glycol may cause nausea, stomach fullness, cramping, diarrhea, and/or gas. Do not take if you have symptoms such as nausea, vomiting, abdominal pain, or distention, which may be due to bowel obstruction. On rare occasions hives and skin rashes have been reported which are suggestive of an allergic reaction. If you get an allergic reaction, you should discontinue the medication and call your doctor.
If you are allergic to polyethylene glycol, do not use this drug.