Mannitol is an isomer of sorbitol. While sorbitol is highly hygroscopic, mannitol is completely non-hygroscopic. Mannitol has a sweet taste equivalent to 70% of sucrose's sweetness.Medically, mannitol serves as an effective diuretic, reducing intracranial and intraocular pressure. It is also used as a renal medication, dehydrating agent, sugar substitute, tablet excipient, and diluent for solids and liquids. As a hyperosmotic hypotensive agent, mannitol injection is a common clinical emergency medication, particularly for cerebral disorders. It rapidly lowers blood pressure with precise efficacy—a critical requirement for drugs reducing intracranial pressure.
[Functions and Effects of Mannitol]
In medicine, mannitol serves as an effective diuretic, reduces intracranial and intraocular pressure, functions as a renal therapeutic agent and diuretic, acts as a sugar substitute, and is used as an excipient in tablets and a diluent for solids and liquids.Mannitol injection, as a hyperosmotic hypotensive agent, is a commonly used drug in clinical emergencies, particularly for brain disorders. It possesses the rapid onset and precise efficacy required of medications designed to reduce intracranial pressure.As a tablet excipient, mannitol exhibits non-hygroscopic properties, rapid drying, and excellent chemical stability. It also offers a pleasant taste and good granulation characteristics, making it suitable for most tablets containing anticancer drugs, antibacterial agents, antihistamines, and vitamins. Additionally, it is used in chewable tablets such as hangover remedies and oral fresheners.In food applications, it exhibits the lowest water absorption among sugars and sugar alcohols while providing a refreshing sweetness. It is used as an anti-caking agent in foods like maltose, chewing gum, and rice cakes, and as a general anti-caking powder for pastries. It also serves as a low-calorie, low-sugar sweetener in foods for diabetics and health foods.Industrially, mannitol is used in plastics manufacturing to produce rosin acid esters and synthetic glycerol resins, explosives, detonators (nitrocellulose), and more. In chemical analysis, it aids in boron determination, while in biological testing, it serves as a bacterial culture medium. Though absorbed by the human gastrointestinal tract, mannitol does not accumulate in the body. After absorption, part is metabolized internally while the remainder is excreted in urine.Dibromomannitol can be produced by reacting with hydrobromic acid.
Used in the synthesis of resins and pharmaceuticals; as a diuretic and dehydrating agent. Treats cerebral edema, glaucoma, acute oliguria, prevents acute renal failure, and manages nephrotic syndrome edema. Intravenous injection is contraindicated in active intracranial hemorrhage (except during craniotomy).[2]
【Clinical Application: Mannitol Injection】
【Indications】
(1) Tissue dehydrating agent. Used to treat cerebral edema of various etiologies, reduce intracranial pressure, and prevent cerebral herniation.
(2) Intraocular pressure reduction. Effectively lowers intraocular pressure when other agents are ineffective or as preoperative preparation for ocular surgery.
(3) Osmotic diuretic. Used to differentiate oliguria caused by prerenal factors or acute renal failure. Also applicable for preventing acute tubular necrosis from various causes.
(4) As an adjunctive diuretic measure for nephrotic syndrome and cirrhotic ascites, especially when accompanied by hypoalbuminemia.
(5) For certain drug overdoses or toxic exposures (e.g., barbiturates, lithium, salicylates, bromides), this drug promotes excretion of these substances and prevents nephrotoxicity.
(6) As an irrigant during transurethral prostate resection.
(7) For preoperative bowel preparation.
【Dosage and Administration】
1. Usual Adult Dose
(1) Diuresis. Usual dose is 1–2 g/kg body weight. Typically administered as 250 mL of 20% solution via intravenous infusion, with dosage adjusted to maintain urine output at 30–50 mL per hour.(2) Treatment of cerebral edema, intracranial hypertension, and glaucoma. Administer 0.25–2 g/kg body weight as a 15%–25% solution via intravenous infusion over 30–60 minutes. Reduce dosage to 0.5 g/kg in debilitated patients. Closely monitor renal function.(3) Differentiating prerenal oliguria from renal oliguria. Administer 0.2 g/kg body weight as a 20% solution intravenously over 3–5 minutes. If hourly urine output remains below 30–50 mL 2–3 hours post-administration, repeat once at most. Discontinue if no response occurs. Use with caution or avoid in patients with existing cardiac impairment or heart failure.(4) Preventing acute tubular necrosis. Administer 12.5–25 g intravenously over 10 minutes. Unless contraindicated, follow with 50 g intravenously over 1 hour. If urine output remains ≥50 mL/hour, continue with 5% solution infusion. Discontinue immediately if ineffective.(5) Treatment of drug or toxin poisoning. Administer 50 g as a 20% solution intravenously. Adjust dosage to maintain urine output between 100–500 mL per hour.(6) Bowel preparation. Administer 1000 mL of a 10% solution orally over 30 minutes, 4–8 hours prior to surgery. 2. Pediatric Dosage (1) Diuresis. Administer 0.25–2 g/kg body weight or 60 g/m² body surface area as a 15%–20% solution intravenously over 2–6 hours.(2) Treatment of cerebral edema, intracranial hypertension, and glaucoma. Administer 1–2 g/kg body weight or 30–60 g/m² body surface area as a 15%–20% solution intravenously over 30–60 minutes. Reduce dose to 0.5 g/kg in debilitated patients.(3) Differentiating prerenal oliguria from renal oliguria. Administer 0.2 g/kg body weight or 6 g/m² body surface area as a 15%–25% concentration intravenous infusion over 3–5 minutes. If urine output does not significantly increase within 2–3 hours post-administration, repeat the dose once. If no response occurs, discontinue use.(4) Treatment of drug or toxin poisoning. Administer intravenous infusion of 5%–10% solution at 2 g/kg body weight or 60 g/m² body surface area.