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  • CLASSES

    Osmotically-Acting Laxatives

    DEA CLASS

    Rx, OTC

    DESCRIPTION

    Osmotic laxative that does not contain electrolytes; no systemic absorption; draws water into the stool to ease bowel movements
    Used to treat constipation in adult and pediatric patients
    Consistently improves constipation even with long-term use; exhibits side effect profile similar to placebo

    COMMON BRAND NAMES

    GaviLax, GIALAX, GlycoLax, Healthylax, MiraLax, Smooth LAX, Vita Health

    HOW SUPPLIED

    GaviLax/GIALAX/GlycoLax/Healthylax/MiraLax/Polyethylene Glycol 3350/Smooth LAX/Vita Health Oral Pwd F/Recon: 17g

    DOSAGE & INDICATIONS

    For the treatment of constipation.
    Oral dosage
    Adults

    17 grams of powder mixed in 120 to 240 mL of fluid (e.g., water, juice, soda, coffee or tea) given PO once daily is the usual dosage. In clinical trials, a dose of 34 grams/day PO was also evaluated; however, the frequency of adverse effects, such as diarrhea, was greater in patients receiving 34 grams/day.

    Adolescents 17 years

    17 grams of powder mixed in 120 to 240 mL of fluid (e.g., water, juice, soda, coffee or tea) given PO once daily is the usual dosage. In clinical trials, a dose of 34 grams/day PO was also evaluated; however, the frequency of adverse effects, such as diarrhea, was greater in patients receiving 34 grams/day.

    Children† and Adolescents† 2 to 16 years

    0.4 grams/kg/day PO initially has been suggested; dose ranges of 0.2 to 1.8 grams/kg/day PO have been reported. Max: 17 grams/day PO. Medical supervision is recommended; non-prescription (OTC) outpatient use should not exceed 2 weeks without further evaluation and medical supervision. One randomized controlled trial of 103 children (mean age, 8.5 +/- 3.1 years) with functional constipation compared PEG 3350 0.2 grams/kg/day, 0.4 grams/kg/day, 0.8 grams/kg/day, and placebo for 2 weeks. By the second week of treatment, all 3 doses significantly increased stool frequency vs. placebo. Bowel movement consistency and straining improved in a dose-dependent manner; however, an increase in GI-related adverse events was noted at the 0.8 grams/kg/day dose. In an observational study (n = 83, including 39 with encopresis), a mean dosage of 0.75 grams/kg/day PO (range, 0.2 to 1.8 grams/kg/day) PO was used for a mean of 8.7 months; the most common side effect (10%) was frequent loose stools, which responded to dosage reduction.

    Infants† and Children† less than 2 years

    0.4 grams/kg/day PO initially has been suggested; dose ranges of 0.2 to 1.5 grams/kg/day PO have been used in studies; in 1 trial of infants and toddlers, the mean effective doses were 0.8 to 1.1 grams/kg/day PO. Medical supervision is recommended.

    For the treatment of fecal impaction†.
    Oral dosage
    Children and Adolescents 2 years and older

    0.25 grams/kg, 0.5 grams/kg, 1 gram/kg, or 1.5 grams/kg PO (not exceeding 100 grams/day PO) and administered in 1 to 4 divided doses for 3 days, were effective in one trial. Impactions resolved in 75% of children overall. The doses of 1 gram/kg/day and 1.5 grams/kg/day were significantly more effective in resolving impactions. All dosages improved stool frequency and were well tolerated.

    For use as a bowel evacuant to clean the colon prior to colonoscopy (bowel preparation)†.
    Oral dosage
    Adults

    This is a second-line treatment regimen per guidelines, not usually recommended. 238 grams PEG 3350 (e.g., Miralax), dissolved in 64 ounces of carbohydrate-electrolyte drink (e.g., Gatorade) PO as a single or split-dose regimen with or without an adjunct laxative (10- to 20-mg bisacodyl tablets). While efficacy of bowel cleansing may be statistically less with this approach, it may have little clinical impact as polyp detection rates remained the same. Concerns regarding this regimen include the risk for electrolyte imbalance, specifically hyponatremia caused by diarrhea-induced volume depletion in the absence of a balanced electrolyte solution replacement. Reserve use for patients who cannot tolerate other bowel preparation regimens and whose risk of complications from electrolyte imbalance is low. Guidelines recommend split-dose over single-dose bowel preparation as a key measure for improving the quality and cost effectiveness of colonoscopies as a screening test.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    34 grams/day PO for daily chronic use.

    Geriatric

    34 grams/day PO for daily chronic use.

    Adolescents

    17 years: 17 grams/day PO for constipation; up to 34 grams/day PO has been studied.
    Less than 17 years: 0.8 grams/kg/day PO (Max: 17 grams/day PO) suggested for constipation. Up to 1.5 grams/kg/day PO (not to exceed 100 grams/day) for short term use for up to 3 days has been used for disimpaction.

    Children

    2 years and older: 0.8 grams/kg/day PO (Max: 17 grams/day PO) suggested for constipation. Up to 1.5 grams/kg/day PO (not to exceed 100 grams/day) for short term use for up to 3 days has been used for disimpaction.
    Less than 2 years: Up to 1.1 grams/kg/day PO has been suggested in some studies off-label for constipation.

    Infants

    Up to 1.1 grams/kg/day PO has been suggested in some studies off-label for constipation.

    Neonates

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

    Renal Impairment

    Specific guidelines for dosage adjustments in renal impairment are not available; patients with renal disease or impairment should only use polyethylene glycol 3350 under supervision and advice of their doctor.

    ADMINISTRATION

    For storage information, see specific product information within the How Supplied section.

    Oral Administration
    Oral Liquid Formulations

    Polyethylene glycol 3350 powder for oral solution can be administered at any time of day; however, administration in the morning is suggested.
    Can be taken orally on a full or empty stomach.
    Measure dosage with the calibrated cap provided with the bulk product, or, open the 17-gram packet (if packet dosing is appropriate). Mix dose well in a full glass (120 to 240 mL or 4 to 8 ounces) of water, juice, soda, coffee, or tea prior to administration. Ensure that the powder is fully dissolved; the patient should not drink if there are any clumps.
    Have patient drink entire prepared dose after it has been dissolved in the proper liquid.
     
     
    Polyethylene glycol 3350 powder for oral solution plus carbohydrate-electrolyte drink (e.g., Miralax + Gatorade) for bowel preparation†
    NOTE: The use of polyethylene glycol 3350 powder for oral solution for bowel preparation is not approved by the FDA.
    Several regimens have been described. One possible split-dose regimen begins by dissolving 238 grams PEG 3350 (e.g., Miralax) in 64 ounces of a lightly colored carbohydrate-electrolyte drink (e.g., Gatorade); may be chilled.
    Day before exam: Patient drinks 32 ounces of solution at a rate of 16 ounces/h starting at 4 PM the day before the colonoscopy; alternatively, the patient may pretreat with 2, 5 mg bisacodyl tablets with clear liquids at 12 PM.
    Morning of exam: Patient drinks the remaining 32 ounces of solution at a rate of 16 ounces/hour, approximately 5 hours before the scheduled start time of the colonoscopy.
    Guidelines recommend split-dose over single-dose bowel preparation as a key measure for improving the quality and cost effectiveness of colonoscopies as a screening test.

    STORAGE

    GaviLax:
    - Store between 68 to 77 degrees F
    GIALAX :
    - Store between 68 to 77 degrees F
    GlycoLax:
    - Store between 68 to 77 degrees F
    Healthylax:
    - Store between 68 to 77 degrees F
    MiraLax:
    - Store between 68 to 77 degrees F
    Smooth LAX:
    - Store between 68 to 77 degrees F
    Vita Health :
    - Store between 68 to 77 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Polyethylene glycol 3350 is contraindicated for use those with known polyethylene glycol hypersensitivity.

    Abdominal pain, acute abdomen, diarrhea, GI bleeding, GI obstruction, GI perforation, ileus, toxic megacolon, vomiting

    Consult a medical professional prior to non-prescription use by a patient if nausea, vomiting or abdominal pain are present, if there has been a recent, sudden change in bowel habits, or if there is a history of irritable bowel syndrome. Polyethylene glycol 3350 solution, like most laxatives, is contraindicated for use in patients with known or suspected GI obstruction. Patients with symptoms suggestive of an acute abdomen, ileus or obstruction, toxic colitis or toxic megacolon, or bowel or GI perforation should be evaluated prior to initiating laxative therapy. Patients should seek advice during the use of polyethylene glycol 3350 if rectal or GI bleeding occurs, diarrhea occurs, or if laxative use is necessary for > 1 week.

    Dementia, dysphagia, esophageal stricture, gag reflex depression

    Due to the potential choking hazard, use polyethylene glycol solution with caution in those patients prone to aspiration or regurgitation (e.g., gag reflex depression, dysphagia, esophageal stricture, impaired mental status or dementia).

    Renal disease

    Patients with renal disease should only use polyethylene glycol 3350 under supervision and advice of their doctor.

    Pregnancy

    Polyethylene glycol (PEG) 3350 is negligibly absorbed and metabolized in humans, making it unlikely to cause malformations. Animal studies do not indicate evidence of fetal harm. The American Gastroenterological Association recommends PEG 3350 as a first-choice laxative in pregnancy when non-pharmacologic methods (e.g., fluids, dietary fiber) are ineffective or inadequate for preventing or treating constipation. A stool softener such as docusate sodium is also considered low risk.

    Breast-feeding

    The safest laxatives for use in lactating women are those that are not systemically absorbed. Polyethylene glycol 3350 (PEG 3350) is a common food additive and is not significantly absorbed from the GI tract. Only 0.2% of an oral dose would be absorbed systemically by the lactating mother. It is not known if PEG 3350 is distributed into breast-milk, but significant passage seems unlikely. The American Gastroenterological Association states that PEG-3350 laxatives represent a low risk when used during breast-feeding.

    Neonates

    Polyethylene glycol 3350 is usually avoided specifically in neonates as a precaution due to the relative lack of clinical data in this age group.

    Geriatric

    In general, polyethylene glycol (PEG) is a safe and effective laxative for non-prescription use in the geriatric patient when used as directed, with adverse reactions similer to those seen in younger adult populations. The federal Omnibus Budget Reconciliation Act (OBRA) regulates the use of medications in residents (e.g., geriatric adults) of long-term care facilities. The OBRA guidelines caution that laxatives may cause flatulence, bloating, and abdominal pain.

    ADVERSE REACTIONS

    Severe

    anaphylactoid reactions / Rapid / 0-1.0

    Moderate

    fecal incontinence / Early / 0-1.0

    Mild

    nausea / Early / 1.0-10.0
    diarrhea / Early / 1.0-10.0
    flatulence / Early / 1.0-10.0
    fecal urgency / Early / 0-1.0
    abdominal pain / Early / 0-1.0
    rhinorrhea / Early / 0-1.0
    pruritus / Rapid / 0-1.0
    urticaria / Rapid / 0-1.0

    DRUG INTERACTIONS

    Acetaminophen; Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Atropine; Difenoxin: (Moderate) Diphenoxylate can decrease GI motility. Drugs used to treat constipation, such as laxatives, would counteract the effect of antidiarrheals. In general, it would be illogical to concurrently administer these drugs at the same time. If an antidiarrheal medication is needed, it would be wise to temporarily discontinue use of agents with laxative effects.
    Atropine; Diphenoxylate: (Moderate) Diphenoxylate can decrease GI motility. Drugs used to treat constipation, such as laxatives, would counteract the effect of antidiarrheals. In general, it would be illogical to concurrently administer these drugs at the same time. If an antidiarrheal medication is needed, it would be wise to temporarily discontinue use of agents with laxative effects.
    Bisacodyl: (Moderate) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Brompheniramine; Guaifenesin; Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Bumetanide: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Calcium Phosphate, Supersaturated: (Moderate) Sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous should not be combined with additional laxatives or purgatives when being used to evacuate the bowel prior to colonic radiologic examinations or surgery. Use in patients using small doses of polyethylene glycol 3350 (e.g., Miralax) may be permissable, as long as the patient does not use their chronic laxative therapy on the day of the preparation. Watch for electrolyte and fluid abnormalities in all patients using bowel preparations.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Casanthranol; Docusate Sodium: (Major) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Castor Oil: (Major) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Chlorpheniramine; Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Dichlorphenamide: (Moderate) Use dichlorphenamide and polyethylene glycol; electrolytes together with caution. Dichlorphenamide increases potassium excretion and can cause hypokalemia and should be used cautiously with other drugs that may cause hypokalemia including laxatives. Measure potassium concentrations at baseline and periodically during dichlorphenamide treatment. If hypokalemia occurs or persists, consider reducing the dichlorphenamide dose or discontinuing dichlorphenamide therapy.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Ethacrynic Acid: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Furosemide: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Guaifenesin; Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Homatropine; Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone; Ibuprofen: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone; Phenylephrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone; Potassium Guaiacolsulfonate: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Hydrocodone; Pseudoephedrine: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as polyethylene glycol, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Lactulose: (Major) In general, other laxatives, such as polyethylene glycol 3350, should not be used concurrently with lactulose, especially during the initial phase of therapy for portal-systemic encephalopathy, because the loose stools resulting from their use may falsely suggest that adequate lactulose dosage has been achieved.
    Loop diuretics: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.
    Pimozide: (Moderate) According to the manufacturer of pimozide, the drug should not be coadministered with drugs known to cause electrolyte imbalances, such as polyethylene glycol used in colon-cleansing regimens, except when indicated. Use in patients using small doses of polyethylene glycol 3350 (e.g., Miralax) may be permissable, as long as not excessive. Pimozide is associated with a well-established risk of QT prolongation and torsade de pointes (TdP), and electrolyte imbalances (e.g., hypokalemia, hypocalcemia, hypomagnesemia) may increase the risk of life-threatening arrhythmias. Pimozide is contraindicated in patients with known hypokalemia or hypomagnesemia.
    Polyethylene Glycol; Electrolytes; Bisacodyl: (Moderate) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Senna: (Major) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Sodium Phosphate Monobasic Monohydrate; Sodium Phosphate Dibasic Anhydrous: (Moderate) Sodium phosphate monobasic monohydrate; sodium phosphate dibasic anhydrous should not be combined with additional laxatives or purgatives when being used to evacuate the bowel prior to colonic radiologic examinations or surgery. Use in patients using small doses of polyethylene glycol 3350 (e.g., Miralax) may be permissable, as long as the patient does not use their chronic laxative therapy on the day of the preparation. Watch for electrolyte and fluid abnormalities in all patients using bowel preparations.
    Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Major) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Stimulant Laxatives: (Major) The use of stimulant laxatives should be avoided in combination with some polyethylene glycol bowel preparation products (e.g., Colyte, Golytely, Nulytely, Moviprep, Plenvu). Concurrent use may increase the risk of mucosal ulceration or ischemic colitis.
    Torsemide: (Moderate) There have been rare reports of generalized tonic-clonic seizures associated with electrolyte abnormalities in patients using polyethylene glycol colon preparation products. In addition, there have been rare reports of serious arrhythmias associated with the use of ionic osmotic laxative products for bowel preparation. Some of these events are associated with electrolyte imbalance. Therefore, polyethylene glycol; electrolytes preparations should be used with caution in patients using concomitant medications that increase the risk of electrolyte abnormalities such as loop diuretics.

    PREGNANCY AND LACTATION

    Pregnancy

    Polyethylene glycol (PEG) 3350 is negligibly absorbed and metabolized in humans, making it unlikely to cause malformations. Animal studies do not indicate evidence of fetal harm. The American Gastroenterological Association recommends PEG 3350 as a first-choice laxative in pregnancy when non-pharmacologic methods (e.g., fluids, dietary fiber) are ineffective or inadequate for preventing or treating constipation. A stool softener such as docusate sodium is also considered low risk.

    The safest laxatives for use in lactating women are those that are not systemically absorbed. Polyethylene glycol 3350 (PEG 3350) is a common food additive and is not significantly absorbed from the GI tract. Only 0.2% of an oral dose would be absorbed systemically by the lactating mother. It is not known if PEG 3350 is distributed into breast-milk, but significant passage seems unlikely. The American Gastroenterological Association states that PEG-3350 laxatives represent a low risk when used during breast-feeding.

    MECHANISM OF ACTION

    Polyethylene glycol 3350 is an osmotic agent which binds water and causes water to be retained within the stool. The lack of intestinal enzymatic degradation or bacterial metabolism of PEG 3350 contributes to the drug's effectiveness for idiopathic constipation; no tachyphylaxis was noted during clinical trials up to 24 months. In normal volunteers, low doses of PEG 3350 increased stool weight. In constipated patients, PEG 3350 softened stool consistency, increased stool frequency, and facilitated stool evacuation. PEG 3350 did not affect colonic transit time. Polyethylene glycol 3350 had no effect on the active absorption or secretion of glucose or electrolytes from the intestine.

    PHARMACOKINETICS

    Polyethylene glycol 3350 is administered orally as a solution in water.
    Complete recovery of an administered dose occurred in the feces of normal volunteers. Roughly 0.2% of a dose has been absorbed systemically in some studies of PEG 3350; the systemically absorbed amount is quickly excreted in the urine. An attempt to study the recovery of PEG 3350 in constipated patients was not reliable, but results are expected to be similar to normal controls. PEG 3350 is not fermented within the GI tract by the colonic microflora; no metabolism occurs locally.

    Oral Route

    After oral administration of polyethylene glycol 3350, the dosage essentially remains within the GI tract.