Mannitol (Mannitol)
Also sold as: Mannitol BP, Osmofundin, Manitol
Pregnancy
Cat C
Lactation
Unknown
Schedule
H
Forms
IV infusion solution (10% — 100g/L; 15% — 150g/L; 20% — 200g/L; 25% — 250g/L)
Indications
- Raised intracranial pressure (cerebral oedema — head trauma, stroke, tumour)
- Raised intraocular pressure (acute angle-closure glaucoma, pre-operative)
- Oliguric acute renal failure — prevention (high-risk surgery, rhabdomyolysis)
- Forced diuresis for drug overdose/poisoning (salicylates, barbiturates, lithium)
- Pre-operative reduction of brain bulk (neurosurgery)
- Haemolytic transfusion reactions (to maintain urine flow)
Adult Dosing
Raised intracranial pressure (cerebral oedema)
0.25–2g/kg IV (20% solution)
Over 30–60 minutes; may repeat every 6–8 hours as needed; maximum 48–72 hours continuous use
Target serum osmolality 300–320 mOsm/kg; STOP if osmolality >320 mOsm/kg (risk of rebound oedema and renal failure); place urinary catheter to measure output; keep head of bed at 30°; monitor ICP if available
Acute angle-closure glaucoma / raised intraocular pressure
1.5–2g/kg IV (20% solution)
Over 30–60 minutes; single dose or repeat once after 4–6 hours
Rapid IOP reduction within 30–60 minutes; definitive treatment (iridotomy) should follow
Oliguric acute renal failure (prevention)
50–100g IV
Over 30–90 minutes; single dose (prophylaxis)
Used pre- or peri-operatively in high-risk cases (aortic surgery, liver transplant, rhabdomyolysis, haemolysis); no evidence of benefit in established AKI
Forced diuresis (drug overdose)
50–200g IV
Over 24 hours at 5–10g/hour; monitor urine output and osmolality
Effective for drugs cleared by renal excretion (salicylates — alkaline diuresis added; barbiturates); maintain urine output >100mL/hour; ensure adequate pre-hydration
Pediatric Dosing
Head trauma/ICP: 0.5–1g/kg IV over 15–30 minutes; monitor osmolality; avoid in neonates unless life-threatening; hypertonic solutions require central or large peripheral line
Renal Dose Adjustment
| CrCl / eGFR | Dose Adjustment |
|---|---|
| Oliguria / acute renal failure | CONTRAINDICATED in established anuria — no mechanism of action; mannitol will accumulate, causing volume overload, pulmonary oedema, and hyperosmolality |
| Mild-moderate CKD | Use with great caution; monitor osmolality and renal function closely; accumulation risk |
Hepatic Adjustment
No hepatic metabolism; excreted unchanged by kidneys. Hepatic failure per se does not alter dosing but coexisting renal impairment (hepatorenal syndrome) is a contraindication.
Pregnancy & Lactation
Pregnancy: Category C
Limited data. Crosses placenta — osmotic load may cause fetal dehydration. Use only for life-threatening maternal indications (e.g. severe raised ICP). Monitor fetal wellbeing.
Lactation: Unknown
No data available. Given that mannitol is used only for acute hospital indications, breastfeeding is typically not an active concern during treatment. Discard milk during IV treatment.
Top Drug Interactions
| Interacting Drug | Effect | Severity |
|---|---|---|
| Cyclosporine | Mannitol increases cyclosporine nephrotoxicity (osmotic tubular damage combined with calcineurin inhibitor nephrotoxicity); monitor renal function closely | Major |
| Lithium | Mannitol increases renal lithium excretion — reduces lithium levels; may be used therapeutically in lithium toxicity but monitor lithium levels | Moderate |
| Digoxin | Mannitol-induced electrolyte shifts (hypokalemia, hyponatraemia) can alter digoxin sensitivity and toxicity risk; monitor electrolytes | Moderate |
| Aminoglycosides | Additive nephrotoxicity; combined osmotic and tubular toxicity; use with caution and monitor renal function | Moderate |
| Blood products | DO NOT mix mannitol with blood — causes pseudoagglutination (red cell clumping); administer through separate IV line | Major |
DoctorScribe — AI Medical Scribe
Stop looking up Mannitol — just speak the prescription
"Mannitol as per dose, BD for 5 days." DoctorScribe writes the full prescription with brand, strength, frequency, and route — auto-applies pediatric weight-based dosing and renal adjustments. Try the live demo.
Side Effects
Common
- Headache (from fluid shifts)
- Nausea and vomiting
- Dry mouth and thirst
- Dizziness
- Chills and fever (during infusion)
- Polyuria (during and after infusion)
- Electrolyte disturbances (hyponatraemia, hypokalaemia)
Serious / Discontinue If
- Acute pulmonary oedema (rapid volume expansion — especially with cardiac compromise or if anuric)
- Severe hyperosmolality (serum osmolality >320 mOsm/kg) — can cause renal tubular necrosis
- Rebound intracranial hypertension (after prolonged use — damaged BBB allows mannitol to accumulate in brain)
- Severe hyponatraemia (paradoxical — dilutional)
- Acute kidney injury (osmotic nephrosis) with prolonged high-dose use
- Extravasation leading to tissue necrosis (hypertonic solution)
- Electrolyte-related cardiac arrhythmias
Contraindications
- Established anuria (confirmed lack of response — no urine despite adequate cardiac function)
- Severe dehydration or hypovolaemia (without concurrent fluid resuscitation)
- Pulmonary oedema (will worsen — initial volume expansion)
- Severe heart failure (volume overload risk)
- Active intracranial bleeding (mannitol may worsen by expanding haematoma)
- Serum osmolality >320 mOsm/kg (stop treatment)
- Known hypersensitivity to mannitol
Available Indian Brands
| Brand | Manufacturer | Price (approx) |
|---|---|---|
| Mannitol 20% 250mL | Baxter | ₹125/bottle |
| Osmofundin 15% 250mL | B.Braun | ₹145/bottle |
Monitoring Required
- Serum osmolality — before and every 2–6 hours during treatment; STOP if >320 mOsm/kg
- Serum sodium, potassium, and creatinine — every 2–6 hours during intensive treatment
- Urine output — hourly via catheter
- Intracranial pressure (ICP) monitoring — if ICP monitor in situ (target <20 mmHg)
- Central venous pressure or fluid balance — to detect volume overload
- Blood pressure and pulse — continuous monitoring in ICU
- Chest auscultation — assess for pulmonary oedema
- Visual acuity and intraocular pressure (for glaucoma indication)
- Serum glucose (mannitol can cause hyperglycaemia in diabetics — small amount metabolised to glucose)
Patient Counseling Points
- Mannitol is given only as an IV infusion in hospital settings — it is not a home medicine.
- You will experience increased urination during and after the infusion — a urinary catheter is usually placed to measure this accurately.
- The infusion must be administered slowly and by trained medical staff — rapid infusion can cause heart and lung problems.
- Report any headache, chest tightness, difficulty breathing, visual changes, or severe dizziness during or after the infusion immediately.
- If you have diabetes, your blood sugar will be monitored closely during mannitol therapy.
- Mannitol must NEVER be mixed in the same IV line as blood transfusion — always check with nursing staff.
- After treatment, regular blood tests (sodium, potassium, kidney function) are essential to ensure no lasting effects.
Stop Googling drug references mid-consultation
EasyClinic auto-flags Mannitol interactions, renal cutoffs, and pregnancy warnings the moment you write the prescription. Built-in safety net for every Indian doctor.
Clinically reviewed by: Dr. Suresh Babu, MD (Medicine), DM (Neurology), MCh (Neurosurgery collaboration), NIMHANS Bangalore
Last reviewed: 2026-04-10
References
- Carney N et al. Guidelines for the Management of Severe Traumatic Brain Injury, 4th Edition. Neurosurgery 2017;80(1):6–15.
- Wakai A et al. Mannitol for acute traumatic brain injury. Cochrane Database Syst Rev 2013.
- Ropper AH. Hyperosmolar therapy for raised intracranial pressure. NEJM 2012;367(8):746–752.
- BNF 86 (2024). Mannitol monograph.
- CIMS India Drug Reference 2024. Mannitol monograph.
- Staykov D et al. Mannitol and hypertonic saline in the treatment of cerebral oedema. J Neurol Sci 2011.