Drug reference

glycerin

Osmotic agent (laxative / ophthalmic / systemic dehydrant) · Diuretic

START

Constipation: 1 suppository PR PRN; IOP/ICP 1–1.5 g/kg PO

TYPICAL MAX

Oral osmotic ~1.5 g/kg per dose

STOP IF

Severe dehydration, hyperosmolar state, or cardiac overload

WATCH

Hydration/electrolytes, glucose (diabetics) with oral dosing

CDSCO approvedATC A06AG04

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 15min · onset
PEAK: 1h · osmotic peak
t½: 36min · t½ (systemic)
DURATION: 4h · oral effect

EXCRETION

Largely metabolised; some renal

route + CYP

INTERACTIONS

—

none in our sources

PREGNANCY

Rectal use considered safe; systemic use only if clearly needed.

FDA category + note

Mechanism

Osmotically active polyol: in the rectum draws water into stool and stimulates evacuation; orally/IV creates an osmotic gradient that transiently reduces intracranial/intraocular pressure.

Indications

Constipation (rectal suppository/enema)Acute reduction of intraocular pressure (oral, pre-op glaucoma)Reduction of cerebral oedema/raised ICP (adjunct, oral)

Dosing

Adult: Constipation: 1 adult suppository (≈2–3 g) PR as needed, or enema. Glaucoma/ICP: 1–1.5 g/kg PO of 50–75% solution (with flavour/ice).
Pediatric: Paediatric suppository (≈1–1.7 g) PR; oral osmotic use specialist.
Renal adjustment: Caution with oral osmotic dosing in renal impairment (fluid/osmolar load).
Hepatic adjustment: Caution in significant hepatic disease (oral load).
Geriatric: Caution with oral dosing (dehydration, cardiac load).
Max dose: Oral osmotic ~1.5 g/kg/dose; rectal as needed