Mannitol

Manna Sugar, Mannite

Mechanism :

Mannitol is confined to the extracellular space, only slightly metabolized and rapidly excreted by the kidney. The drug is freely filtered by the glomeruli with less than 10% tubular reabsorption; it is not secreted by tubular cells. Mannitol induces diuresis by elevating the osmolarity of the glomerular filtrate and thereby hindering tubular reabsorption of water. Excretion of sodium and chloride is also enhanced.

Indication :

• Cerebral edema
• Anuria/Oliguria

Contraindications :

Known hypersensitivity to mannitol, pulmonary edema or congestive heart failure, dehydration and/or acidosis, intracranial bleeding, anuria due to severe renal disease, progressive renal damage or dysfunction after institution of mannitol therapy, including increasing oliguria and azotemia are contraindications for its use.

Dosing :

Adverse Effect :

Pulmonary congestion, acidosis, marked diuresis, sore throat, vomiting, electrolyte loss, dryness of mouth, thirst, edema, cough, fluid and electrolyte imbalance, laboured breathing, urinary retention, headache, blurred vision, chills, nausea, convulsions, arm pain, skin necrosis, thrombophlebitis, urticaria, dizziness, dehydration, hypotension, tachycardia, fever and angina-like chest pains.

Interaction :

Aminoglycosides: Mannitol potentiates ototoxic effects.
Lithium: Renal excretion of lithium may be increased.
Neuromuscular Blocking Drugs: Effects of competitive or depolarizing neuromuscular blockers may be enhanced.
Oral Anticoagulants: Mannitol may reduce the effect of anticoagulant drugs.
Digoxin: Increased risk of digoxin toxicity if mannitol administration produces hypokalemia.
Cisplatin: Mannitol reduces the toxicity of cisplatin.
Antihypertensives: May induce hyponatremia
Other drugs include: Sodium bisphosphonate, droperidol, fentanyl, hyoscyamine, bisacodyl, methenamine, methylene blue.

Hepatic Dose :