GLYCOLAX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GLYCOLAX (GLYCOLAX).
Osmotic laxative. Polyethylene glycol (PEG) increases intraluminal water volume in the colon by osmosis, promoting stool passage and relieving constipation.
| Metabolism | Not metabolized; excreted unchanged in feces. |
| Excretion | Minimally absorbed; excreted primarily unchanged in feces via osmotic action. Renal excretion negligible (<0.2% absorbed dose). |
| Half-life | Not applicable due to negligible systemic absorption; local colonic transit time approximately 2-4 hours. |
| Protein binding | Not bound (polyethylene glycol not bound to plasma proteins). |
| Volume of Distribution | Not applicable due to minimal absorption; if absorbed, distributes largely in extracellular fluid; Vd negligible. |
| Bioavailability | Oral: <0.2% (systemic absorption negligible); rectal: minimal systemic absorption. |
| Onset of Action | Oral: 6-12 hours; rectal: 2-5 minutes (for constipation), 30-60 minutes (for bowel evacuation). |
| Duration of Action | Oral: 24-48 hours (bowel movement within 24 hours for constipation); rectal: 2-4 hours for evacuation. |
17 g (1 heaping tablespoon) dissolved in 4-8 ounces of liquid once daily, orally.
| Dosage form | FOR SOLUTION |
| Renal impairment | No dose adjustment required, but use with caution in patients with renal impairment due to risk of electrolyte disturbances. |
| Liver impairment | No dose adjustment required; use standard dosing for patients with hepatic impairment. |
| Pediatric use | For children 2-11 years: 8.5 g (1/2 heaping tablespoon) dissolved in 4-8 ounces of liquid once daily; for children 12 years and older: same as adult dosing. |
| Geriatric use | Use with caution due to increased risk of electrolyte disturbances and dehydration; consider lower starting dose (e.g., 8.5 g once daily) and monitor electrolytes and fluid status. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GLYCOLAX (GLYCOLAX).
| Breastfeeding | Polyethylene glycol 3350 is minimally absorbed systemically (<0.1%), making excretion into breast milk negligible. The M/P ratio is not defined due to lack of detection in plasma. Likely safe during breastfeeding. |
| Teratogenic Risk | Polyethylene glycol 3350 (GlycoLax) has no known teratogenic effects. Animal studies show no fetal harm. Human data are limited but no increased risk of major congenital malformations has been reported. Use in all trimesters is considered low risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Serious Effects |
Bowel obstruction, ileus, gastrointestinal perforation, toxic colitis, toxic megacolon, known hypersensitivity to PEG.
| Precautions | Use beyond 1 week may cause dependence; caution in patients with bowel obstruction, ileus, or gastrointestinal perforation; risk of electrolyte disturbances with prolonged use. |
Loading safety data…
| No specific monitoring required beyond routine prenatal care. Monitor for electrolyte disturbances if used chronically or in large doses. |
| Fertility Effects | No known effects on fertility in animal or human studies. Polyethylene glycol is not systemically absorbed and does not impact reproductive function. |