Comparative Pharmacology
Head-to-head clinical analysis: MIRALAX versus OSMOPREP.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MIRALAX versus OSMOPREP.
MIRALAX vs OSMOPREP
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Polyethylene glycol 3350 (PEG 3350) is an osmotic laxative that works by retaining water in the stool through hydrogen bonding, increasing fecal water content and promoting bowel movements.
Osmotic laxative. Sodium phosphate draws water into the intestinal lumen via osmotic gradient, increasing intraluminal pressure and stimulating peristalsis.
17 g (1 heaping tablespoon) dissolved in 4–8 oz of water, juice, soda, coffee, or tea, administered orally once daily. Maximum duration of use: 7 days.
3 tablets orally in the evening before colonoscopy, followed by 3 tablets the next morning, each dose with at least 1.5 L of clear liquids; maximum 6 tablets total.
None Documented
None Documented
Not applicable; polyethylene glycol 3350 is minimally absorbed and systemic half-life is not clinically relevant.
The terminal elimination half-life of the absorbed fraction is approximately 2.7 hours. This short half-life indicates rapid renal clearance of the small amount absorbed; however, the clinical effect (bowel cleansing) is independent of systemic elimination.
Primarily excreted unchanged in feces (>90% of oral dose); negligible renal elimination (<0.1% recovered in urine).
Osmoprep (sodium phosphate monobasic monohydrate and sodium phosphate dibasic anhydrous) is not significantly absorbed systemically; the majority of the administered dose remains in the gastrointestinal tract and is eliminated in the feces. Less than 1% of the dose is absorbed and subsequently excreted unchanged in the urine via renal filtration.
Category C
Category C
Osmotic Laxative
Osmotic Laxative