Sorbitol and Mannitol

INDICATIONS AND USAGE Sorbitol-Mannitol Irrigation is indicated for use as a urologic irrigating fluid during transurethral prostatic resection and other transurethral surgical procedures.

DOSAGE AND ADMINISTRATION Sorbitol-Mannitol Irrigation should be administered only by transurethral instillation with appropriate urologic instrumentation. A disposable administration set should be used. The total volume of solution used for irrigation is solely at the discretion of the surgeon. Height of container(s) above the operating table in excess of 60 cm (approx. 2 ft) has been reported to increase intravascular absorption of the irrigating fluid. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever container and solution permit. (See PRECAUTIONS .)

WARNINGS FOR UROLOGIC IRRIGATION ONLY. Solutions for urologic irrigation must be used with caution in patients with severe cardiopulmonary or renal dysfunction. Irrigating fluids used during transurethral prostatectomy have been demonstrated to enter the systemic circulation in relatively large volumes; thus, sorbitol-mannitol irrigant must be regarded as a systemic drug. Absorption of large amounts of fluids containing sorbitol-mannitol and the osmotic diuresis it produces may significantly alter cardiopulmonary and renal dynamics. Hyperglycemia from metabolism of sorbitol may occur in patients with diabetes mellitus. Hyperlactatemia from metabolism of sorbitol may potentially produce a significant lactic acidemia in metabolically compromised patients. The contents of an opened container should be used promptly to minimize the possibility of bacterial growth or pyrogen formation. Discard the unused portion of irrigation solution since it contains no preservatives. Do not heat over 66°C (150°F).

CONTRAINDICATIONS NOT FOR INJECTION BY USUAL PARENTERAL ROUTES. Do not use in patients with anuria.

ADVERSE REACTIONS Adverse reactions may result from intravascular absorption of sorbitol and mannitol. The literature reports occasional adverse reactions from intravenous sorbitol-mannitol infusions. Consequences of absorption of urologic irrigating solutions include fluid and electrolyte disturbances such as acidosis, electrolyte loss, marked diuresis, urinary retention, edema, dryness of mouth, thirst and dehydration; cardiovascular disorders such as hypotension, tachycardia, angina-like pains; pulmonary disorders such as pulmonary congestion; and other general reactions such as blurred vision, convulsions, nausea, vomiting, diarrhea, rhinitis, chills, vertigo, backache and urticaria. Allergic reactions from sorbitol-mannitol have also been reported. Should any adverse reaction occur, discontinue the irrigant, evaluate the patient, institute appropriate therapeutic countermeasures and save the remainder of the fluid for examination if deemed necessary.

CLINICAL PHARMACOLOGY Sorbitol and mannitol are hexitols and are nonelectrolytes. A solution of these constituents in water is therefore nonconductive and suitable for urologic irrigation during electrosurgical procedures. A 3% (approx.) total concentration of sorbitol-mannitol contains sufficient solute to minimize the risk of intravascular hemolysis which can occur from absorption of plain water through open prostatic veins during transurethral resection (TUR). Any solution that is absorbed intravascularly during transurethral prostatic or bladder surgery, although variable in amount depending primarily on the extent of surgery, will be excreted by the kidney. When absorbed intravascularly, sorbitol and mannitol act as osmotic diuretics. Intravascular absorption of sorbitol has been shown to produce elevations of serum lactate after TUR above preoperative values owing to sorbitol's favored metabolism to lactate from pyruvate. Increased lactate levels were not sufficient to produce evidence of metabolic acidosis. Mannitol is only slightly metabolized and rapidly excreted by the kidney.