LAXATIVE PEG 3350 (Generic for POLYETHYLENE GLYCOL 3350)

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

Route-Specific Administration

Oral Administration
Oral Liquid Formulations
-Can be taken orally on a full or empty stomach.
-Polyethylene glycol powder for oral solution can be administered at any time of day; however, administration in the morning is suggested. Use should not exceed 7 days.
-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. Do NOT combine with starch-based thickeners.

Polyethylene glycol 3350 (PEG 3350) is a relatively safe agent for the short-term treatment of constipation. Clinical trials to date have evaluated the safety and efficacy of PEG 3350 in doses of 17 grams/day in adults for up to 6 months. Flatulence and nausea may occur infrequently. Abdominal pain, bloating and cramping may occur rarely. Higher doses (e.g., 34 grams/day) may produce diarrhea and excessive stool frequency, particularly in elderly, debilitated patients, and may result in dehydration (rare). In some patients excessive stools may rarely cause fecal urgency or fecal incontinence. A reduction in dosing may resolve loose stools. Discontinue PEG 3350 if diarrhea occurs. In children aged 3 to 18 years in a trial for fecal impaction, common side effects were similar to those seen in adults and included bloating, flatulence (18%), loose stools (13%) or diarrhea, nausea (5%) and abdominal cramps (5%). Cases of choking and potential aspiration were reported in patients with dysphagia who received polyethylene glycol (PEG) mixed with starch-thickened liquids; when PEG solution is mixed with starch-thickened liquids, it reduces the viscosity of the starch-thickened liquid resulting in thinning of the liquid.

Isolated cases of pruritus, urticaria, rhinorrhea, dermatitis and (rarely) anaphylactoid reactions have been reported which may represent allergic reactions. Polyethylene glycol compounds are found in numerous medications and food additives, and have been reported to cause allergic reactions.

Patients should not use polyethylene glycol 3350 if they have a known polyethylene glycol hypersensitivity.

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.

Due to the potential choking hazard, use polyethylene glycol (PEG) oral solution with caution in those pediatric patients prone to aspiration or regurgitation (e.g., gag reflex depression, dysphagia, esophageal stricture, or impaired mental status). Do not combine PEG oral solutions with starch-based thickeners. When a PEG-based product used for another indication was mixed in starch-based pre-thickened liquids used in patients with dysphagia, thinning of the liquid occurred and cases of choking and potential aspiration were reported.

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

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

Description: Polyethylene glycol 3350 (PEG 3350) is an osmotic laxative used to treat occasional constipation. Polyethylene glycols exhibit practically no systemic absorption from the intestine at molecular weights exceeding 3000. Polyethylene glycol 3350 has been used clinically for decades for various gastrointestinal purposes, most commonly as an essential component of colonic lavage solutions. Polyethylene glycol 3350 is recognized as an effective means of treating constipation as well as fecal impaction in pediatric patients as young as 2 years of age. In May, 2019 the FDA determined that there is no meaningful difference between single-ingredient prescription-only PEG 3350 and OTC PEG 3350 products; patients requiring single-ingredient PEG 3350 may be encouraged to purchase either MiraLax or generic PEG 3350 products over the counter, without a prescription.

For the treatment of constipation:
Oral dosage (e.g., MiraLax):
Infants* and Children* less than 2 years: 0.4 gram/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 a trial of infants and toddlers, the mean effective dose range was 0.8 to 1.1 grams/kg/day PO.
Children* and Adolescents* 2 to 16 years: 0.4 gram/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 7 days without further evaluation and medical supervision. In one randomized controlled trial, the authors noted efficacy, but did report an increase in GI-related adverse events with doses 0.8 gram/kg/day or more. In an observational study (n = 83, including 39 with encopresis), a mean dose of 0.75 gram/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.
Adolescents 17 years: 17 grams PO once daily is the usual dose, mixed in appropriate fluids. OTC use should not exceed 7 days without medical supervision and advice. In clinical trials, dosages of 34 grams/day PO were also evaluated; however, the frequency of adverse effects, such as diarrhea, was greater in those receiving this higher dose.

For the treatment of fecal impaction*:
Oral dosage (e.g., MiraLax):
Infants* and Children* < 2 years: The use of PEG 3350 has not been evaluated in children and infants < 2 years of age; children and infants in this age group have been excluded from clinical trials. Safety and efficacy have not been established.
Children >= 2 years* and Adolescents*: 0.25 g/kg, 0.5 g/kg, 1 g/kg or 1.5 g/kg PO, (up to a maximum of 100 g/day PO) administered in 1-4 divided doses for 3 days, were effective in one trial. Impactions resolved in 75% of children overall. The 1 g/kg/day and 1.5 g/kg/day doses were significantly more effective (95%) than lower dosages (55%) in resolving impactions. All dosages improved stool frequency. The drug was well tolerated for this purpose.

Maximum Dosage Limits:
-Neonates
Safety and efficacy have not been established.
-Infants
0.4 g/kg/day up to 1.1 g/kg/day PO has been suggested in some studies for functional constipation.
-Children
<= 2 years: 0.4 g/kg/day up to 1.1 g/kg/day PO has been suggested in some studies for functional constipation.
> 2 years: 0.8 g/kg/day PO (Max: 17 g/day PO) suggested for functional constipation. Up to 1.5 g/kg/day PO (Max: 100 g/day PO), for short term use of <= 3 days for disimpaction.
-Adolescents
< 17 years: 0.8 g/kg/day PO (Max: 17 g/day PO) suggested for functional constipation. Up to 1.5 g/kg/day PO (Max: 100 g/day PO), for short term use of <= 3 days for disimpaction.
>= 17 years: 17 g/day PO for constipation; up to 34 g/day PO has been studied.

Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

Patients with Renal Impairment Dosing
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.

*non-FDA-approved indication

Monograph content under development

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 2 weeks of use during clinical trials. In normal volunteers, low doses (e.g., 17 g/day) 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. Pharmacodynamically, relief of constipation is expected within 1-3 days of use.

Affected cytochrome P450 isoenzymes: none


-Route-Specific Pharmacokinetics
Oral Route
After oral administration of polyethylene glycol 3350, the dosage essentially remains within the GI tract.